Gardening in South Africa http://www.gardeninginsouthafrica.co.za Sat, 21 Jul 2018 07:28:29 +0000 en-gb If you want a truly beautiful plant that is as tough as old boots - you need a Sagewood! http://www.gardeninginsouthafrica.co.za/index.php/1245-january/if-you-want-a-truly-beautiful-plant-that-is-as-tough-as-old-boots-you-need-a-sagewood http://www.gardeninginsouthafrica.co.za/index.php/1245-january/if-you-want-a-truly-beautiful-plant-that-is-as-tough-as-old-boots-you-need-a-sagewood


Buddleja salvifolia 'Mauve' Picture courtesy www.kumbula.nursery.co.zaSagewood, Saliehout, ewanci, igwangi, chipambati, lelothwane, umbataewepe, mupambati
(Buddleja salviifolia)

This beautiful small tree or large shrub is a member of the wild elder family and is called Buddleja salviifolia because of its wonderful dark green sage-like leaves which are conspicuously wrinkled and puckered above, and densely covered with whitish hairs below, giving them a distinctive silvery colour. An abundance large flower panicles droop down from the plant, appearing from August to October, and varying in colour from white, to lilac and purple. The flowers are followed by fruits which are little hairy capsules.

The flowers are full of nectar and have an intoxicating sweet honey-like perfume, attracting many species of butterflies, bees, other insects, and insect-eating birds. If you site your sagewood somewhere in the garden where you can stay for a while, when this tree is in bloom you are likely to see a variety of birds, dependant on the region where you live. It is visited by Arrow marked babblers, Kurrichane thrushes, Fork tailed drongos, Southern black tits; and if you’re really lucky, one of our many colourful Cuckoo species, or even a Bee eater.

Sagewood is also the host plant for only one species of butterfly, the African leopard (Phalanta phalantha aethiopica.) The leaves are browsed by Eland, Bushbuck, Nyala, Kudu and Impala. For all these reasons, sagewood is essential for all wildlife and fragrant gardens, so treat yourself to one, you will be delighted, as will many other creatures large and small!

Proudly, this is one of our most beautiful indigenous trees (SA Tree No: 637) and is common from the Western Cape through the Eastern Cape, to the Free State, Lesotho, Kwazulu-Natal, Northern Province and Mpumalanga; extending into Mozambique, Zimbabwe and tropical Africa. It does well near water and beside streams, growing naturally in groups on the edges of wooded areas; in sheltered areas near exposed rocky habitats; and often near drainage lines along lower slopes.

Sagewood is semi-evergreen, dropping some of its leaves in winter.  In the wild it grows quickly to +-3 to 8m tall, producing numerous branches from the main stem, and as these lengthen, they droop gracefully downwards. For garden culture, it is generally sold as a large shrub, 2 to 3m tall, with an equal spread. It can, however, be pruned to keep it smaller.

Buddleia salviifolia. picture courtesy www.newplant.co.zaUses:

The fresh or dried leaves make an aromatic herbal tea, which can also be applied as an eye lotion. The wood is hard and is often used to make fishing rods; and in the past assegais and spear shafts were also made from the wood.

In the Garden:

Sagewood is an excellent choice for busy gardeners who want a low-maintenance and water wise plant which still rewards with beautiful flowers. It is also remarkably tough and resistant to pests and diseases, reducing the need to spray. And, if you wish to attract all types of wild life to your garden, you will find sagewood a great all-rounder.

It is an excellent pioneer plant, providing protection for slower growing plants and trees in new gardens. It will recover quickly from fires, re-shooting from the rootstock; and because it loves growing near water and has a vigorous root system, is perfect to stabilise slopes near river banks and dams.

Sagewood usually grows into a beautifully shaped shrub in the garden but it can be pruned to keep it smaller, and even trained into a lovely small tree. If pruned often it forms an excellent windbreak, informal screening plant, or hedge.

This plant has aggressive roots and because of its size, should not be planted too close to buildings and foundations.

Cultivation/Propagation:

Sagewood thrives in full sun but can also be grown in semi-shade. One of its greatest qualities is its ability to grow in a saline environment, making it an excellent choice for coastal gardens, where it will take fierce, salty winds. Sagewood is also hardy to moderate frost, but  in cold frosty regions try to site your plant in a warm area which is sheltered from cold winds, and protect young plants from frost until they are well established.

Once established, sagewood is remarkably frost, heat and drought tolerant, making it fantastic for water-wise gardens.  Watering moderately during prolonged dry periods will keep it looking its best in the garden. Care should be taken when transplanting, as the roots are very delicate.

This plant grows quickly and easily in very sandy soils with poor nutrition, but will adapt to most garden soils with excellent drainage. In poor soils, adding compost to the planting hole and a generous dusting of bone meal will get your plants off to a good start. Once established the shrubs will need no further feeding, but an occasional sprinkling with a balanced fertiliser, and a seasonal mulching around the roots with compost or kraal manure, will keep it looking great.

Sagewood can be clipped into shape any time after it has flowered, but should be pruned back at least once a year by about one third in order to produce more flowering shoots.

The fastest means of propagation is by taking semi-hardwood or hardwood cuttings in summer. Treat them with a root stimulating hormone powder and plant the cuttings in washed river sand; keep the soil moist but not soggy until roots have formed. Seeds also germinate readily but may not reproduce true to the parent plant.

Problems, Pests & Diseases:

If the sagewood is happy where it is growing it suffers from no serious pests or diseases, and insects like caterpillars, bugs and aphids etc. will do no serious harm.

Warning:

This plant is not listed in any poisonous databases and Buddleja davidii is listed as nontoxic to humans, with no data suggesting it is toxic for dogs, cats or other pets. If they chew on the plant they will get no more than a stomach ache. However, it is always best to prevent children and pets from eating flowers or leaves.

This plant has aggressive roots and because of its size, should not be planted too close to buildings and foundations.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Wed, 30 May 2018 13:36:59 +0000
The Saucer Magnolia is a magnificent tree or large shrub and one of the most sought after ornamentals. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-saucer-magnolia-is-a-magnificent-tree-or-large-shrub-and-one-of-the-most-sought-after-ornamentals http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-saucer-magnolia-is-a-magnificent-tree-or-large-shrub-and-one-of-the-most-sought-after-ornamentals

Magnolia soulangeana. Picture courtesy Karl Gercens - see his flickr pageMagnolias have a long history as magnificent additions to the garden, no matter the time of year, but especially in late winter and spring when their naked branches are festooned with startling cup, or saucer-shaped flowers. Discovered in the Orient, Magnolias were named in honour of the 17th century botanist Pierre Magnol, and have graced western gardens for more than 300 years. The saucer magnolia remains one of the most commonly used magnolias in horticulture, being widely planted in the British Isles, especially in the south of England; and the east and west coasts of The United States.

All winter large green, fuzzy flower buds are carried at the tips of brittle branches, shimmering in the weak sunshine, and once they open, the effect of the blooms against the light grey bark is quite spectacular, taking one's breath away! The flowers are fragrant and usually white, flushed with purple on the outside, but there are many colour variations, from pure white to cream and shades of pink and purple, and if you're lucky, a few additional flowers may bloom sporadically in summer. Fruits are often absent on this hybrid but may appear in late summer, releasing individual, red coated seeds suspended on slender threads.

New leaves are reddish bronze, maturing to large oval, shiny, dark green leaves, turning yellow before dropping again in autumn. The saucer magnolia is typically a small, multi-stemmed tree or large shrub whose growth is upright when young, developing a spreading, rounded crown with maturity. Magnolias are valued for their longevity, and the saucer magnolia grows +-5 to 7.5m tall with a spread of +-3 to 5m. Growth is fairly quick at first then slows down considerably as the tree reaches about 20 years of age.

Magnolia soulangeana. Picture courtesy Peter RichardsonThe family Magnoliaceae is widely distributed in temperate and tropical Asia, from the Himalayas to Japan, and southwest through Malaysia and New Guinea. East and south-east Asia is its main distribution centre with approximately two thirds of the species. The remainder of the family is spread across the Americas with temperate species extending into southern Canada, and a few tropical species extending into Brazil and the West Indies.

Today we know that the Magnolia is a very ancient genus which evolved even before bees appeared, because fossilized magnolia flowers, along with their beetles, were discovered in rocks dating around 100 million years old! Due to its great age, this family of plants has survived major geologic events such as ice ages, continental drift and mountain formation, causing its distribution to become fragmented, isolating some species while keeping others in close proximity.

These plants can be found growing in dense woodlands and forests on moist, humus-rich soils; and although they occur mainly in tropical and subtropical climates, many varieties are quite hardy. They are represented by over 240 species and hundreds of varieties, both deciduous and evergreen, all of which are also highly diverse in their growth habit, ranging from tall trees to various sized shrubs.
The saucer magnolia is a magnificent garden hybrid which was initially bred from (M. denudata x M. liliiflora) by French plantsman Etienne Soulange-Bodin in the early 1800s. Plant breeders in many countries continue to develop this magnolia, and over a hundred named cultivars are now known, so you are sure to find your perfect one!

Picture courtesy Green Acres Nursery CaliforniaIn the Garden:

The saucer magnolia will start blooming after 4 to 5 years and can be pruned into a large shrub or small tree.  Plant it where its great beauty can be enjoyed - it makes a wonderful specimen flowering tree and is invaluable in a mixed tree and shrub border. If planted close to a walkway or patio it can be pruned up to allow for pedestrian clearance, but if left to take on its natural shape the branches will droop right down to the ground, making an incredible display.

If space is limited in your garden and you simply have to have a magnolia, consider growing one in a large container, the saucer magnolia does quite well in pots.

Magnolias are also well-suited to espalier. Espalier is the practice of controlling woody plant growth by tying the branches to a wooden or wire frame so that they grow into a flat plane; frequently in formal patterns, against a structure such as a wall, fence, or trellis.

Espalier, trained into flat two-dimensional forms, are ideal not only for decorative purposes, but also for gardens in which space is limited. Also, in cold regions, if trained against a sunny wall or fence it will afford protection and warmth during the cold winter months. Despite this practice, reports of damage to the foundations of buildings or walls, is uncommon.

Initially the young shoots are bent down and tied very gently to only about 45 degrees, or they may break. During the growing season they can be encouraged into the more horizontal position required to train them along the frame. Prune regularly to remove any shoots growing towards the wall, and shorten outward-growing ones to one or two leaves. If these outward-growing shoots have flower buds, pruning can be delayed until immediately after flowering.

Picture courtesy Lotus Johnston - see her flickr pageCultivation/Propagation:
 
Magnolias are easy to grow and relatively pest free, and once established will need the minimum of attention. The saucer magnolia grows best in cool areas with good rainfall and mild winters. The plant itself is fully hardy, but the flowers are tender and often reduced to sad rags by late frosts and freezing winter winds. In cold regions position the plant in a sheltered part of the garden where it will not be exposed to very early morning sunshine in the winter, as this will burn the frosted buds and flowers - a position with early shade and sun later in the day is best. Thick mulch around the roots will help prevent them from freezing. The saucer magnolia also has moderate salt spray tolerance, but it is best to have more protection, such as a fence or building, as an additional barrier behind the first row of plantings or the first dunes.

The saucer magnolia can be grown in full sun or semi-shade, but requires adequate sun to flower well. In sub-tropical and hot zones it is best to plant it in a cool spot where it will be sheltered from the fierce midday sun and hot winds. In the winter rainfall regions it must be watered regularly throughout summer, and planted in a wind protected spot. In these regions it is also essential that the soil has excellent drainage. Magnolias are not suitable for the very dry parts of the country, and in all regions it is most important to water regularly during dry spells. Mulching the roots in summer will help to retain moisture and keep them cool.

Because of its shallow root system the magnolia is sensitive to root disturbance, and is also very fussy about its depth of planting. Never plant it deeper than it is growing in its nursery bag, and keep mulch well away from the trunk. Once established magnolias are not easily transplanted, so ensure you plant it in the correct position.

It is important to prepare the planting holes well because specimens grown in heavy, compacted, or poorly drained soil will appear stunted. The saucer magnolia thrives in a slightly acidic, loamy, well-drained soil which is rich in organic matter and which retains moisture throughout the year. However, it is more tolerant of alkaline soils than other magnolias. In alkaline soils, prepare the planting holes well, adding lots of acid compost and other organic material. To encourage faster growth, feed with a balanced fertiliser during the growing season.

If you wish to train your plant, do this when it is still young, because older plants do not like to be pruned, and large wounds may not close well.

Cuttings, layering, and grafting are the preferred methods of propagation. After a layered branch has rooted, it can be cut from the parent stock and survive on its own.

Problems, Pests & Diseases:

The saucer magnolia suffers from no serious insect or disease problems but is susceptible to sooty mould associated with scale; and the limbs may break in strong winds and during heavy storms.

Warning:

Happily the saucer magnolia is listed as non-toxic, but it is always sensible to keep pets and small children from chewing on plants.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Thu, 31 May 2018 14:25:19 +0000
The beautiful Krantz Aloe produces its profusion of warmly coloured flower spikes during the drab winter months when not much else is blooming in the garden. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-beautiful-krantz-aloe-produces-its-profusion-of-warmly-coloured-flower-spikes-during-the-drab-winter-months-when-not-much-else-is-blooming-in-the-garden http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-beautiful-krantz-aloe-produces-its-profusion-of-warmly-coloured-flower-spikes-during-the-drab-winter-months-when-not-much-else-is-blooming-in-the-garden

 

Aloe arborescens Picture courtesy www.newplant.co.zaThe beautiful krantz aloe is a valuable garden asset and possibly the most widely cultivated aloe in the world. It is cherished for its profusion of warmly coloured flower spikes during the drab winter months when not much else is blooming in the garden. From May to July it bears flowers in fiery shades of deep-orange, which is the most common colour, but there are also forms with colours like salmon pink, a deep orange-red, and also a lovely butter-yellow colour. Plant breeders have even developed striking bi-coloured hybrids which are sure to delight.

In South Africa we are proud to call this beauty our very own and it is gracing more and more gardens, much to the delight of humans, birds and other wildlife, providing them will a valuable food source when this is scarce. In the wild the krantz aloe is concentrated mainly in the eastern summer rainfall areas, but it can also be found from the Cape Peninsula and along the eastern coast, through KwaZulu-Natal, Mpumalanga and Limpopo provinces. It occurs in low coastal scrub to high mountain tops, and although it is adaptable to many habitats, favours exposed sunny ridges and rocky outcrops.

When in full bloom the krantz aloe is easy to spot in the wild, but even when not in bloom it still stands out in the landscape with its stately form, up to 2 to 3m tall, and its spreading habit, producing a multi-headed shrub of striking green leaves armed with sharp teeth at their margins, and arranged in attractive rosettes.
 
Because Aloe arborescens hybridises readily with other aloes, the species formerly known as Aloe mutabilis is now regarded as a form of Aloe arborescens. This hybrid is smaller growing than the krantz aloe and is more evident on the high inland plateau of the northern provinces of South Africa, where it grows on cliffs and produces gorgeous red and yellow bi-coloured flower spikes.

Uses:

Aloe arborescens is the only other member of the aloe family that is claimed to be as effective as Aloe Vera for medical uses. The sap of the leaves has many uses and has been used to treat stomach ailments for many centuries, as well as abrasions, burns and skin ailments. The Zulu people use the leaves of this plant as a protection against storms, and in the Transkei it is used for stomach ache and given to chickens to prevent them from getting sick. Extracts from the leaves have been widely researched and have shown significant wound healing, anti-bacterial, anti-ulcer, anti-inflammatory, anti-carcinogenic, hypoglycaemic and also alopoeic activity.

In the Garden:

The krantz aloe is easy to grow, extremely water-wise, and also a 'must-have' for anyone wanting to stock their herb gardens with indigenous healing plants - good reasons to include at least one of these decorative aloes in your garden.

Because it grows into a large and spreading plant the krantz aloe is very useful for larger gardens, and a valuable accent plant with its attractive foliage and decorative form. It can also be grown as an excellent and impenetrable hedging plant. The flowers produce copious amounts of nectar, attracting many birds, especially sunbirds, as well as butterflies, bees and other insects.

Cultivation/Propagation:

The krantz aloe grows quickly in the garden, and is a wonderful low-maintenance and water-wise plant. It is a great coastal plant and does just as well inland, tolerating moderate frost and drought.  It will always look its best in the garden, however, if it is watered judiciously during long dry spells.

All aloes thrive in full sun, and the one thing they are all really fussy about is perfect soil drainage, otherwise they will adapt to most soil types. Adding some compost to the planting hole, along with a generous dressing of bone meal will get your plant off to a good start. Mulching around the roots in autumn with compost or kraal manure will be sufficient to ensure glorious blooms in winter.

The krantz aloe is easily propagated from branch or stem cuttings. Allow the branches to dry for a day, or until the wound has sealed, before planting into well-drained soil or washed river-sand. Do not overwater the cuttings or they may rot. Seed can be sown in spring, taking about 3 to 4 weeks to germinate.

Problems, Pests & Diseases:

Aloe rust shows as small, pale yellow spots on leaves which expand and turn brown; orange spore masses may be present on underside of leaf; leaves may drop from plant. Disease emergence favours cool temperatures and high humidity. Although this disease is self-limiting and requires no treatment, it is unsightly and may be treated with a suitable fungicide if necessary.

Anthracnose disease shows initially as small round to oval, dark green water-soaked spots, which later become circular with tan to light brown centres. As the spots mature the centre of the lesion becomes reddish-brown to brown in colour, progressing to form lesions which join together to form big necrotic areas. This fungal disease is favoured by warm, wet weather, and is spread easily during wet weather by water splash. It can be controlled by the application of a suitable fungicide.

Basal stem rot turns the base of the plant reddish brown to black and causes rotting. This is a fatal disease of aloes and its emergence favours cold, damp conditions. Try to save pieces of the plant which are not infected by taking cuttings above the rotted portion.

Bacterial soft rot symptoms show as watery, rotting leaves which are darker in colour; young leaves wilting and collapsing, and bulging leaves due to gas formation inside. This fatal disease can be avoided by not overwatering plants. This bacterium survives in plant debris in the field, and its emergence is favoured by hot, wet weather.

Aphids feed at the bases of the leaves or in the rolled ends of damaged leaves. They secrete sticky, sweet honeydew, which results in sooty mould development. Severe infestation leads to slow growth and stunting. Organically acceptable methods of control include the application of insecticidal soap and preservation of natural enemies.

Adult Snout Beetles feed off of Aloe leaves, their presence can usually be detected by the presence of circular lesions that have a transverse slit in the centre. Snout Beetles lay their eggs at the base of aloe leaves, and after the larvae have hatched they bore into the stem just below the crown which usually results in the death of the plant.

Warning:

Aloe arborescens is the only other member of the aloe family that is claimed to be as effective as Aloe Vera for medical uses, and although these two aloes have a rich history in the realm of natural healing, producing a clear, gelatine-like substance that soothes burns and relieves skin conditions such as psoriasis when used topically, they can be toxic in certain circumstances.

Just below the outer skin of the aloe plant’s leaves is a layer of yellow juice. This juice, also known as the plant’s latex and contains a natural chemical called “aloin.” Aloin is a type of anthraquinone glycoside, which may irritate your skin if you have an allergy to latex. The skin irritation or allergy associated with latex is known as contact dermatitis, which produces a localized rash.

Aloe latex contains powerful laxative properties, and the ingestion of aloe juice or latex may also irritate the intestines when taken orally.If aloe latex is consumed in large quantities it can lead to diarrhoea. Serious bouts of diarrhoea in young children and animals may result in loss of electrolytes and dehydration. If you suspect the ingestion of aloe latex by a young child or animal, it is important to seek medical advice.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Tue, 29 May 2018 07:33:10 +0000
With the proper care and a favourable rootstock, a citrus tree is capable of producing fruit in excess of 50 years! http://www.gardeninginsouthafrica.co.za/index.php/1245-january/with-the-proper-care-and-a-favourable-rootstock-a-citrus-tree-is-capable-of-producing-fruit-in-excess-of-50-years http://www.gardeninginsouthafrica.co.za/index.php/1245-january/with-the-proper-care-and-a-favourable-rootstock-a-citrus-tree-is-capable-of-producing-fruit-in-excess-of-50-years

 
OrangesCitrus trees can be so pretty, even in the smallest of gardens. They have gorgeous shiny green leaves, beautiful sweet-smelling flowers, and wonderful health-giving fruit packed with vitamin C and antioxidants. The genus Citrus is native to south-east Asia, occurring from northern India to China and south through Malaysia, the East Indies and the Philippines, and records of domestication go back to about 500 BC.

Citrus is big business in South Africa and we are the second-largest exporter of oranges, grapefruits and lemons in the world. Citrus is grown in three different climatic regions; the cool coastal areas of the Eastern and Western Cape, Kwa-Zulu Natal, the semi tropical areas of Limpopo and Mpumalanga, and tropical areas like Nelspruit and Letaba. The Sundays River Valley, north of Port Elizabeth in the Eastern Cape, is world-renowned for being able to produce almost any kind of citrus, thanks to both its special climatic conditions and its location in a valley, not too close to the sea. Despite its hot summers, which allow the area to produce fruit with high sugar content, the Eastern Cape is regarded as a cool citrus producing area, with the cold, frost-free winters assuring good colour development. Both of the above results in the excellent quality of the navel oranges and lemons it produces. The Sundays River Valley takes the traveller into an evergreen world of citrus trees, and in October when the trees are in full bloom, the warm air of the Valley is heavy with their perfume.

With the proper care, good cultural practices, and a favourable rootstock, a citrus tree is capable of producing fruit in excess of 50 years. One such example is the original Washington Navel orange brought first from Brazil to Washington D.C. - then to California - in 1873. One hundred years later it was still alive and producing fruit.

In the Garden: Citrus do need quite a bit of tender loving care, but will reward you with bumper crops if their specific needs are met; and by choosing different varies, will provide you with fresh citrus for up to nine months a year. Citrus make the perfect evergreen garden tree and grow beautifully in pots in courtyards or on balconies. Any variety can be grown in a tub, providing the container is a decent size. Generally, Kumquats and Calamondins are very well-suited to tub-culture, as are Meyer Lemons and Lime trees. Of all the lemons for pots, you can't get much better than the 'Meyer'. I't's got a really nice tight bunching habit and produces plenty of fruit. It is not as acidic as the 'Eureka' lemon, is full of juice and great for cooking. If you are planting citrus in a pot, use a good quality potting mix and water and feed regularly.

Selecting Citrus for Your Garden:

The first step toward successfully growing citrus trees is to take the time to find out which varieties grow best in your area and to purchase them from a reputable nursery. Citrus trees are subtropical to tropical in nature and they suffer severe damage or even death because of freezing temperatures. However, several types of citrus have sufficient cold-hardiness to sustain some freezing conditions, particularly as mature trees. The tree you select should have healthy, deep green leaves, the trunk should be straight and the tree should be able to support itself without a stake. Young grafted trees will start producing fruit when still very young, but it is best to remove all fruit until the trees are more mature; fruiting takes a lot of energy from the young tree and by removing it, the plant can conserve energy, allowing it to adapt to the stresses of its new environment and grow new roots and leaves.

Good citrus yields are particularly dependant on both summer and winter temperatures. For the best quality fruit, the temperatures should not be too hot in summer, or too cold in winter. In colder regions plant them in a warm sheltered position in the garden away from cold winds and cover them in winter if necessary, until they are established. A nearby reflective wall, fence, or even patio can provide both shelter and extra warmth. Lemons are semi-hardy to moderate frost and other citrus cultivars are available that have been bred to be more resistant to cold, so check your varieties carefully.

In regions that experience moderate frost (-3°C to -5°C) you can grow Lemons, Kumquats, and Satsuma Mandarins in a very sheltered part of the garden, or in large pots on sheltered patios. Cover young plants with a protection cover in winter until they are established.

In regions with mild winter frost (-1°C to -2°C), Lemons and certain varieties of Valencia and Navel Oranges, Naartjies, Satsumas, Clementines, Mandarines and Kumquats can be grown in a sheltered position. Calamondins will tolerate brief spells of frost.

Fruiting & Harvesting: With the exception of lemons, which flower up to four times per year, most citrus varieties flower in spring. The buds appear in early August, and by early October the last petals fall, leaving the tiny fruitlets behind. A mature citrus tree can produce hundreds of thousands of blossoms, yet only about two percent of these will result in edible fruit. This heavy blossom production is nature's way of assuring that insects, attracted by the tree's fragrance, pollinate the maximum number of flowers. Seventy to eighty percent of the flowers will drop during and immediately following bloom. A second drop of small pea-sized fruits a couple of weeks after blooming will occur; this is perfectly natural.

Depending on the variety, a citrus tree is capable of producing anywhere from 1 to 1000 pounds of fruit per season. Maximum yields will vary according to the variety grown, weather conditions, cultural care, the age of the tree, and many other factors. Fortunately, the fruit from citrus trees does not mature in the span of a few weeks as deciduous fruit does. Most citrus fruit should be allowed to ripen on the tree, and the longer it remains on the tree, the less acidic and sweeter it will become. Ripened fruit will hold on the tree for 3 to 4 months, allowing you to harvest as required. Oranges, lemons, and grapefruit should all be completely free of green colouring as they will not ripen off the tree. Limes are generally picked green, so go by size and season.

Growing Citrus: Generally citrus can be planted all year round, except in colder regions where it is best to avoid planting in the winter months. Spring is the main season for growers to plant their open rooted and potted trees, but in regions where the spring weather warms up very quickly, planting in late summer and autumn (March to April) will give the young trees ample time to become established before the temperatures become too hot. Citrus form small, compact evergreen trees, and are usually slow growing. The best site is a warm sunny spot, protected from strong winds; trees grown in semi shade will not bear as much fruit and the tree will be more susceptible to disease and insect attacks. Most citrus grows well in a soil pH range from 6 to 8. Avoid soils that are excessively salty, as citrus trees will not grow well in such soils. Excellent drainage is essential, as they do not like waterlogged roots. Citrus have a shallow root system, with feeder roots close to the surface of the soil, so any cultivation around them must be quite shallow. Organic mulches must be kept at least 30cm away from the trunk of the tree because of their potential for inducing foot rot disease and bark infection. 

Watering: How often you need to water your citrus trees will depend on the composition of the soil, how well it drains, and your rainfall. They grow best when they are flooded with water and then allowed to dry out before re-watering. Overwatering can be just as much of a problem as not watering enough. During the summer months, established trees can be watered deeply about every 7 to 10 days and in winter every 2 to 3 weeks. Newly planted trees will require more regular watering until they are established. Water well during dry, warm weather, or they may prematurely drop their flowers or developing fruit. Once established, the trees may tolerate some drought, but the quality of the fruit will be affected.

Planting: Planting your citrus tree at the proper depth is the most important factor. Plant the tree too low and the trunk will stay wet, and this will encourage bark diseases. Plant it too high and the root ball will dry out too quickly and not enough moisture will get to the tree. Young citrus trees must be planted in deeply dug, well drained soil with added compost, but no fertiliser. Young trees should not be fertilised until they start showing new growth. The practice of scooping out grass and soil to form a large depression for ease of watering, almost guarantees the death of a citrus tree. Try to avoid planting citrus in the middle of the lawn, as the lawn will compete for moisture and food and your tree may become stunted, unless it is given extra care.

Feeding: Established citrus trees require moderately heavy nutrients and even on very fertile soils will require feeding after a few heavy crops. Feed them three times a year - in July, December and March - with a balanced fertiliser that has a high nitrogen and medium potassium level (8:1:6 is fine for the home gardener.) During the first few years of growth, give your tree 300g at each application and then increase it to 500g. Gradually increase this amount yearly, until your tree is fully mature and receiving 2,5kg per application. In addition, give the tree 75g of Epsom salts (magnesium sulphate) three times a year. Mature, bearing citrus trees should receive enough nitrogen to provide for good but not excessive leaf growth. Never fertilise close to the trunk and spread it uniformly on the soil surface under the tree canopy to slightly beyond the drip line, and water it in thoroughly. It is not necessary to drill holes in the soil for fertilisers as a thorough watering will carry surface-applied fertiliser throughout the soil.

Pruning: Citrus trees do not require severe pruning and can be allowed to grow naturally, as much as is practically possible. Pruning citrus can be beneficial for fruit production when it is done in such a way as to allow more light and air to penetrate the canopy of the tree.  Allow your trees to branch as low down as possible, if you prune your branches too high your tree will produce less fruit. Aim to have four to six well-positioned, scaffold branches by the first year of bearing. These scaffold branches grow laterally from the tree trunk, providing the framework of the mature tree. In subsequent years, remove extra scaffold branches and thorny water shoots, as well as any suckers growing from the rootstock below the graft. Pruning is also done to remove dead, diseased or damaged wood. Any strong upright shoots which are taller growing than the rest of the tree will eventually bend forward. If you must remove this strong growth, cut out the branch completely, as shortening it will only aggravate the problem. "Wild" shoots that are growing beyond the general shape of the tree can also be removed. These will often be long, straight, quick-growing branches that don't follow the overall form or shape of the tree. Seal all large cut branches with a good tree sealer to avoid infection.

Weeds: All weeds need to be removed regularly by hand, because the shallow feeder roots and trunk are easily damaged by tools; and wounds promote the penetration of soil pathogens in the plant, causing root rot. Weeds also act as pathways for ants.

Propagation:

Citrus trees are not grown from seeds because plants grown from seed are not always true to the parent plant and you can never be certain what kind of plant you are going to get and how well it will produce. Citrus naturally have a weak rootstock, so they are grafted onto a stronger more vigorous rootstock.

CITRUS VARIETIES: Citrus in South Africa are divided into cultivar groups and each cultivar group has unique climatic requirements and are dependent on temperature, heat units, day length, light and humidity.

Calamondins & Kumquats (Citrofortunella X mitis & Fortunella japonica)
These garden hybrids are beautiful ornamental trees that produce abundant crops of miniature fruits for a long time. They are grown for their ornamental value and to make preserves. Standard plants are available that look wonderful planted in tubs. They will grow about 2m tall and 2m wide and are semi-hardy to frost if they are planted in a sheltered place.

Lemon (Citrus x limon)
Lemons are the most useful garden trees and are native to South East Asia. Lemon is used in drinks, and for flavouring a wide variety of foods. The essential oil from Lemon is known as cedro oil, and is used as flavouring in the food industry and is also used in soaps, detergents and perfumes. Lemons are easy to grow and will tolerate colder weather than other citrus, but the trees will be damaged if the temperature drops to -7°C at night.  'Meyer' is best in colder regions, and produces heavy crops of smooth fruit with a thin rind, on almost thornless stems. 'Eureka' is a very popular variety that grows taller than 'Meyer' and is also a heavy cropper, producing large, smooth-skinned fruits with few or no pips; it is also almost thornless. Other varieties include: 'Lisbon', 'Genoa' and 'Limoniera'. The trees will grow about 3m tall and 2 to 3m wide. The 'Cape' or 'Rough' lemon (Citrus jambhiri) is very thorny, with a thick, rough skin.

Limes
Limes originate from tropical Southeast Asia, where they can still be found growing in the wild. There are several varieties, each with its own characteristic flavour. Cultivars have been developed based on sweetness (usually sour), size, shape (round or oblong) and colour (yellow or green). All varieties have relatively thin skins. Lime fruits are used for preserves, garnishes and juices, and Citral oil is extracted for use in perfumes.

The Persian Lime, Tahiti Lime, Bearss Lime (Citrus latifolia)
The seedless fruit is about 6cm in diameter, often with slightly nippled ends, and is mainly used for fresh consumption. It is usually sold quite green, but turns yellow as it reaches full ripeness. The Persian lime is larger than the Key lime and thicker-skinned, but is not as aromatic, and is less acidic. The trees are only suitable for frost-free regions and will grow about 2 to 4m tall and 2 to 3m wide.

The Key Lime, West Indian Lime, Mexican Lime (Citrus aurantifolia)
The Key Lime is valued for its unique, tart flavour compared to other limes. It is smaller, seedier, has higher acidity, a stronger aroma, and a thinner rind than that of the Persian lime. It is usually sold quite green, but turns yellow as it reaches full ripeness. It is used mainly for its juice and rind oil production, for preserving, and to a lesser extent, fresh consumption.

ORANGES (Citrus sinensis)
Oranges are native to China and South Vietnam. They are highly ornamental garden plants that look beautiful even without fruit.

Navel Oranges only produce good quality fruit in cool subtropical and temperate Mediterranean climates. They mature early and are great dessert oranges because they are seedless, are relatively easy to peel and have excellent flavour. They are not as productive as Valencia oranges and severe climatic conditions during flowering and fruit set can negatively impact on yields. Early maturing navels like 'Navelina' and 'Newhall' are harvested in April and May. Mid maturing varieties like 'Bahianinha', 'Palmer', 'Cara' and 'Washington', are harvested in May and June. Late maturing navels like 'Lane Late', 'Cambria', 'Glen Ora' and 'Witkrans'are harvested in June and July. Navel oranges vary in height according to the variety, but will grow about 5m tall and 3 to 5m wide.

Valencia Oranges are ideal for the home garden. The fruit is smaller than navels with a thinner rind and few seeds, and no navel. They are very sweet and are good for juicing and eating, even though they are more difficult to peel than navels.  They have a high acid content and mature later than navels. The early maturing varieties like 'Turkey' and 'Benny' are harvested in June and July, the mid maturing varieties like 'Midknight' and 'Delta' in July and August, and the late maturing varieties like 'Du Roi', 'Valencia Late' and 'McLean' from July to September. Valencia oranges vary in height according to the variety, but will grow about 5m tall and 3 to 5m wide.

Seville, Bergamot or Sour Orange (Citrus x aurantium)
The sour orange is a hybrid between 'Pummelo' (Citrus grandis ) and 'Mandarin' (Citrus reticulate). It originates in China and the oldest written records appeared around 300 BC. Because of its bitter taste, the sour orange is not usually eaten raw, but rather for making marmalade and candied peel. It is also used to produce essential oils for use in soaps and perfume, for fruit extracts that are used to flavour soft drinks, and in distilling certain liqueurs.

Mandarins, Tangerines, Naartjies & Tangelos (Citrus reticulata)
Mandarines, tangerines, tangelos and naartjies are all interrelated. The Mandarin was probably domesticated in tropical Southeast Asia. By 500 BC it was known in China and by 400 AD grafting methods were being used to clone favourable varieties. It was introduced to Japan at an early stage, and it was here that the Satsuma variety was developed.

Mandarins produce delicious fruits with loose rinds and are best suited to regions with cool to cold winters, where the temperatures do not drop below 5°C. They don't do well in hot tropical and subtropical regions. Varieties include: 'Satsuma', 'Clementine', 'Nova', 'Empress' and 'Tambor'. The trees will grow about 3 to 4.5m tall and 4,5m wide.
 
Tangelos were bred from Mandarin 'Deliciosa', which was crossed with a grapefruit to produce a tasty, firm, red-skinned hybrid that is called a Tangelo. The 'Orlando' and 'Minneola' tangelo originated as a cross between a 'Duncan' grapefruit and a 'Dancy' tangerine. Tangelos generally have loose skin and are easier to peel than oranges. They are easily distinguished from oranges by a characteristic knob at the top of the fruit. The fruits are the size of an adult's fist and have a tangerine taste, but are very juicy, producing excellent and plentiful juice. Several cultivars of Tangelo have been developed; like 'Minneola', 'Orlando', 'Seminole' and 'Sampson'.  They will grow about 4.5m tall and 3.5m wide.

Tangerines and Naartjies fruit best in regions where the winter temperatures do not drop below 5°C and will grow about 3 to 4.5m tall and 4.5m wide. Varieties include: 'Cape', 'Fagan', 'Groenskil' and the Japanese 'Satsuma' and 'Oonshu'.

Grapefruit (Citrus x paradisii)
Grapefruit is a West Indian hybrid that is widely grown commercially and in gardens. They thrive in frost-free areas and the fruit develops best in subtropical regions. The trees get quite large, 3 to 6m tall and 3m wide, and are only suitable for large gardens. They are distinguished by their high acid levels and large fruits. 'Red Blush' and 'Rosa' have a lovely pinkish flesh with good flavour and size. 'Star Ruby' and 'Flame' have red flesh, and 'Marsh's Seedless' has white flesh, and 'Marsh' has white flesh and 'Marsh's Seedless' has very large, sweet fruit.

Shaddocks (Citrus maxima)
Shaddocks are also called Pummelo or Pamplemousse and are thought to have originated in South East Asia. They are generally larger than grapefruit, with lower acid levels and firmer juice vesicles.

CITRUS DEFICIENCIES:

YELLOW LEAVES: It is not uncommon for citrus leaves to go yellow during winter or after a heavy cropping of fruit and this can be corrected in spring with fertilisation. Yellowing can also occur if the ground is too wet and the drainage is not excellent. Mineral deficiencies can also cause a yellowing and mottling of the foliage and it is usually a deficiency of iron, zinc, magnesium or manganese that is causing the problem. Zinc deficiency shows a fishbone-like pattern on the leaves with a yellowing between the leaf veins.Manganese deficiency cause yellow blotches between the leaf veins. Magnesium deficiency is fairly common, especially in autumn. The leaves will go yellow with a green V-shaped area at the base leaf. To correct this give a mature tree 2,5kg of magnesium sulphate (Epson Salts) and for a young tree about 250g. Iron deficiency Citrus may exhibit Iron deficiency in the early spring. Usually the deficiency clears up as the soil warms up. If it does not, a soil application of iron chelate should sort out the problem. Clay soils usually contain plenty of iron, but where iron deficiency does occur, do not use fertilizers which contain phosphorous because high phosphorous aggravates iron and zinc deficiency in high pH (alkaline) soils. Red, sandy soils may need supplemental potassium and sandy soils may need additional zinc. Nitrogen: Mature citrus trees should receive enough nitrogen to provide for good but not excessive leaf growth.

PESTS & DISEASES: The use of pesticides in the home garden should be restricted to a minimum and whenever possible, organic products should be used. There is a natural balance in nature between pests and their natural predators, and when pesticides are used continuously this balance is disturbed, and a vicious cycle is created; resulting in the trees having to be sprayed all the time. Apart from the damage caused to the environment, the cost factor can also be enormous. Insects occasionally trouble citrus trees in home gardens and may require spraying, but rarely will these pests render the fruit inedible or seriously threaten the health of the plant. Good cultural practices will help to keep insects and diseases to a minimum and citrus can easily be grown organically. If you do have spray, always use organic products and follow the dilution rates and spraying times meticulously and always add a wetter/sticker to the spray mixture. Citrus leaves are very glossy and a sticker helps the spray stick to the leaves.

Ants: The brown house ant and the pugnacious ant are the one of the most important insects to control near citrus trees, because they protect and 'farm' certain insects like scale and aphids, for the honeydew they secrete. Ant nests, particularly those of the pugnacious ant, if present underneath or near the trees, must be treated immediately. Ludwigs Insect Spray is a broad spectrum insecticide that contains garlic juice, canola oil and natural pyrethrum. It is certified to control ants and many other garden insects. Canola oil kills small-bodied insects on contact by means of suffocation, and garlic keeps insects away from plants. Pyrethrum has a stomach poison activity of about 24 hours. This formulation has a very low toxicity to mammals, with no secondary poisoning. It is however, toxic to fish and moderately toxic to bees. Edible crops can be harvested 48 hours after applying.

Scale Insects: There are many types of hard (armoured) and soft scale insects, and they can be various colours, like brown, red, purple, grey, white,  green etc. Pernicious and red scale, as well as soft brown scale are a common problems on citrus as well as many other garden plants, and can be present all year round. A sure sign that you have scale is if there are ants running up and down the branches. Young scales are mobile crawlers and adult males have tiny wings, making them more mobile than the females. Mostly, the adults attach themselves to the bark, leaves and fruit, sucking out the plant sap through their needle-like mouthparts.  Scale insects generally excrete honeydew, on which a fungus called sooty mould grows. Sooty mould is black and looks worse than it really is, and doesn't hurt the leaves or fruit. Scale insects are 'farm' by ants for their sugary excretions, and in return, the ants protect the scale from their natural predators like; ladybirds and their larvae, lacewings and predatory thrips. Many types of scale are controlled satisfactorily by their natural enemies, provided ants are kept out of the trees, get rid of the ants around your trees and the sooty mould and the scale will disappear. Severe infestations can cause the leaves to turn yellow and drop and may kill young trees. It will cause die-back of the twigs and can kill entire branches on more mature trees. To control bad infestations, remove all badly infested branches completely in winter and burn them. The best time to spray for scale is also in winter but mineral oils can be sprayed in summer, as long they are applied during the coolest part of the day. Mineral oils like Oleum work the best, killing most species of scale on contact. If infestations are very severe you should apply three applications within 10 days, ensuring full coverage of the tree. Products containing Canola oil, like Margaret Roberts Insecticide will also suffocate scale. Ludwigs Insect Spray is a broad spectrum insecticide that contains garlic juice, canola oil and natural pyrethrum. It is certified to control many garden insects. Canola oil kills small-bodied insects on contact and garlic keeps insects away from plants. Pyrethrum has a stomach poison activity of about 24 hours. This formulation has a very low toxicity to mammals, with no secondary poisoning. It is however, toxic to fish and moderately toxic to bees. Edible crops can be harvested 48 hours after applying.

Brown Citrus Aphid: Aphids are soft-bodied insects that suck the sap from plants and can therefore spread viral diseases from one plant to another. Young aphids are wingless and adults can be winged or wingless. The various species vary in colour and can be dark brown, light and dark green, red-brown, pale yellow, grey and black. The aphids secrete honeydew which attracts ants and other insects. The ants farm the aphids for the honeydew, and in return, protect the aphids from their natural predators such as ladybirds, parasitic wasps and praying mantis. Aphids love fresh new plant growth and can cause distorted and malformed growth, and stunting of the plants growth. Black sooty mould is a fungus that grows on the honeydew, but this fungus will not damage the leaves or fruit. Get rid of the aphids and ants and the mould will disappear. Margaret Robert's Organic insecticide controls small-bodied insects and is authorised for use in organic agriculture. It contains garlic juiced extract and canola oil and is used to control aphids and many other garden insects. Canola oil kills small-bodied insects on contact by means of suffocation, and garlic keeps insects away from plants. It has a low impact on bigger bodied beneficial insects and natural predators and the product is harmless to fish, birds, wildlife, pets and humans. However, never allow oil formulations to form a layer over water surfaces as huge quantities of any oil will cut off the oxygen supply to aquatic organisms, resulting in harm to aquatic life like fish and frogs. No harmful toxic residues remain in the environment for prolonged periods and edible crops can be harvested within 24 hours.

Citrus Thrips: Severe attacks by thrips will cause young shoots and leaves to become thickened and distorted, and developing shoots may turn black and fall off. During development, the peels of young citrus fruit can also be blemished by citrus thrips. This mostly starts from the stem end and may spread downwards, extending over the rest of the fruit, but does not, however, affect the eating quality of the fruit. Ludwigs Insect Spray is a broad spectrum insecticide that contains garlic juice, canola oil and natural pyrethrum. It is certified to control thrips as well as many other garden insects. Canola oil kills small-bodied insects on contact by means of suffocation, and garlic keeps insects away from plants. Pyrethrum has a stomach poison activity of about 24 hours. This formulation has a very low toxicity to mammals, with no secondary poisoning. It is however, toxic to fish and moderately toxic to bees. Edible crops can be harvested 48 hours after applying.

Citrus Psylla: Psylla causes unsightly bumps on the leaves, especially the fresh young leaves, and is caused by citrus gall wasps. They are the transmitter of a major citrus disease known as greening. (See Greening). Citrus trees have three growth flushes a year: one in August/September, followed by another in November/December and the last during February/March. Lemons are the exception, forming new leaves throughout the year. It is during these flushes that the trees are susceptible to psylla infestation. The female citrus gall wasp lays discernible orange-yellow eggs on the edges of the young leaves. When the eggs hatch, the young nymphs move to the underside of the leaves and establish themselves to feed, causing pock-like malformations on the leaves. Control of the pest must be aimed at destroying the nymphs as soon as possible after they have hatched. Because all the eggs do not hatch at once, it is essential to use a spray with a fairly long residual action and to spray regularly - as subscribed on the bottle. Check your trees regularly for the eggs and begin spraying immediately, ensuring that all the leaves are thoroughly covered.

Citrus Leaf Miner: Leaf miner attacks can occur at any time of the year, especially in warm and humid regions, causing the leaves to curl and go brown, with distorted twisted new growth, and squiggly lines in the leaves. This pest can really make the trees look unsightly. There are several types of leaf miner and tiny moths, beetles or flies are the adult stage. Damage to plants is done at the larval stage, when they feed within the leaves, and heavy infestations will affect yields. Leaf miners need to be controlled, especially in young trees, by spraying every time they put out a new flush of leaves. The insects can be found on weeds, flowers and vegetables, so keep the ground around your trees weed- free. The best control is obtained when infestations are detected at an early stage. Physically removing infected leaves will  help control larvae growing inside the leaves, and spraying with a contact poison containing Canola oil or natural Pyrethrins will control the adults, if sprayed weekly. Ludwigs Insect Spray is a broad spectrum insecticide that contains garlic juice, canola oil and natural pyrethrum. It is certified to control many garden insects. Canola oil kills small-bodied insects on contact and garlic keeps insects away from plants. Pyrethrum has a stomach poison activity of about 24 hours. This formulation has a very low toxicity to mammals, with no secondary poisoning. It is however, toxic to fish and moderately toxic to bees. Edible crops can be harvested 48 hours after applying.

Citrus Mealybugs: There are many mealybug species; they are small white, oval insects that are covered in mealy waxy threads. They can be found on the undersides of the leaves, the leaf joints, and crevices, where they are not easily noticeable. Mealy bugs are a common garden pest. They suck the sap of plants and can therefore transmit viruses. If infestations are severe, they can cause severe wilting of the soft, new shoots, leaf discolouration and severe leaf drop, yellow spots may develop on citrus fruits.  The sweet honeydew they secrete will cause sooty mould to grow on their secretions. Sooty mould looks worse than it really is and doesn't hurt the leaves or fruit. Mealy bugs are protected and 'farmed' by ants for these sugary excretions. If you get rid of the ants, so that the natural predators of mealy bugs can help control their populations, the mealybugs and the sooty mould will disappear. Natural predators of mealybugs are ladybirds, parasitic wasps, lacewings and small birds. Mealbug infestations can occur at any time of the year and winter is an ideal time for them to breed in sheltered areas of the garden. Spring and late summer are the best months to spray for control because their natural predators may also be affected by sprays and they are not as active in the cooler months. Mealybugs can be treated with the same pesticides as for scale and aphids. White mineral oils like Oleum and organic insecticides containing canola oil and natural pyrethrins are effective, suffocating the insects on contact. Ludwigs Insect Spray is a broad spectrum insecticide that contains garlic juice, canola oil and natural pyrethrum. It is certified to control many garden insects. Canola oil kills small-bodied insects on contact and garlic keeps insects away from plants. Pyrethrum has a stomach poison activity of about 24 hours. This formulation has a very low toxicity to mammals, with no secondary poisoning. It is however, toxic to fish and moderately toxic to bees.Edible crops can be harvested 48 hours after applying.

Fruit Flies: Fruit flies attack many species of fruiting plants and cause post-harvest decay on fruit. Fruit flies look like a small housefly and the clear wings have orange and brown patterns. When they rest on fruit the wings are usually horizontal. In South Africa the most common species are the Mediterranean and Natal Fruitfly. Infestations can occur all year round but seem to peak from January to March. They sting the fruit and lay their eggs just below the surface, right after the blossoms have fallen, as well as when the fruit is ripening. The eggs hatch within three days and the small white maggots begin feeding. Signs of fruit fly infestation will show as a sticky gum oozing out of the still green fruit. After a few weeks the fruit is entirely rotten and falls to the ground. The maggots then burrow into the soil to pupate. Within two weeks a new generation of fruit fly emerges and a new cycle begins. There are several eco friendly ways to combat this destructive cycle. In May or June brush the tree trunks and any large branches of your fruit trees with a medium hard brush to remove hibernating insects. Remove all mulch and fallen debris from the ground and burn it. In spring, when your trees start to bloom, place a lining of frost cover/ bidum/weed guard on the ground around your trees. This will prevent mature fruit fly, that have survived the winter in the soil, from emerging from the ground. Once 80% of the blossoms have fallen from your tree you can start spraying with wormwood and garlic or a quassia spray every week. Spray the entire tree as well as the ground around it. Try to do this in the early evening when the bees are in their hives. Organic formulations like Ludwigs Insect Spray contain pyrethrins and can also be applied every 2 weeks. Baited traps can also be hung in the trees.Continually remove any fruit that appears to be stung and keep good hygiene on the ground.

Orange Dog Caterpillars: These can sometimes become a problem in the garden, especially on immature trees, because the larvae feed mainly on the young leaves. The damage caused is the same as for any leaf-eating caterpillars, but seldom will the larvae reach epidemic proportions and a few caterpillars on mature trees will not affect the health of the trees. The culprit is a beautiful butterfly called the citrus swallowtail, which emerges in spring. It has large wings with bright yellow and black markings, with the distinctive swallowtail at their bases. The spiny backs of the young larvae are black with a white mark. As the larvae mature they become smoother and turn green, with a diagonal black stripe on both sides of the back, and black stripes across the head.  They can reach 40mm long and larvae can be present from late spring to autumn.  If only a few are present, they can be collected by hand or you can spray with Margaret Roberts Biological Caterpillar Insecticide, which is a natural product that will control orange dog caterpillars as well as many other garden insects. It contains no toxic residues and is harmless to bees, birds, fish, pets, wildlife, beneficial insects and natural predators. It can cause harm to the young larvae of butterfly species, but has no effect on adult butterflies. It is safe to use on edible crops and they can be harvested directly after application.

Sooty Mould: This fungus looks worse than it really is and doesn't hurt the leaves or fruit. This fungus grows on the sugary deposits made by scale insects, aphids and mealybugs, which are protected and farmed for their sugary excretions, by ants. Get rid of the ants and the mould will disappear.

Citrus Black Spot: is common in tropical to subtropical regions. This fungal disease affects many garden plants and is most noticeable on roses if the humidity is high and during prolonged wet weather, especially in autumn. Infection shows on the leaves by the appearance of dark brown to black spots, followed by a yellow radiance around the edges and can result in leaf drop. Mancozeb 800 WP is an organic fungicide which controls black spot and many other fungal diseases on edible crops. Scab usually becomes less of a problem as the trees grow older, but routine spraying may often continue to be necessary, particularly on the more susceptible varieties.

Scab: This fungus that can affect the leaves, twigs, and fruit, of susceptible citrus varieties. It can be particularly severe on lemon trees and also occurs on minneolas, tangelos and grapefruit, but rarely on sweet oranges. The symptoms are a corky roughness on the leaves and young twigs. The disease starts as small, pale orange, roughly circular, elevated spots that develop well-defined protuberances on one side of the leaf, often with a conical depression on the opposite side. The tops of these wart-like growths usually become covered with a scabby, corky tissue, and the infected spots can often run together, covering large areas. The leaves of badly infected plants become crinkled and distorted and the twigs will develop small masses of similar corky outgrowths on the surfaces. Scab starts on the fruit by forming irregular scabby spots or caked masses that start off cream to pale yellow and develop to a dull olive-grey with age. Bad infections will cause the fruit to become misshapen, with wart-like or conical growths extending from the surface. On grapefruit the infected areas tend to flatten out, resembling wind scar injury. The spores are spread by rainfall, heavy dew, irrigation systems, and to some extent by wind. Warm, wet summer weather is ideal for spore germination, when the temperatures reach 24 to 28°C. To control scab two to three applications of fungicide need to be applied. Citrus scab is similar to apple and pear scab and is treated in the same way. The trees should be sprayed in early spring when the first flush of new leaves is a few centimetres long. The second application is made at petal fall, and the last one is applied about 3 weeks later. Mancozeb 800 WP is an organic fungicide which controls scab and many other fungal diseases on edible crops. Scab usually becomes less of a problem as the trees grow older, but routine spraying may often continue to be necessary, particularly on the more susceptible varieties.

Blossom-end Rot: causes a brown patch of rot on end on the ripened fruit where the blossoms were attached. It is mainly caused by the fruit being over-mature on the tree.

Phytophthora: This is a serious disease that affects citrus. It affects the lower trunk and/or root system of the plant. If this fungus is present in your soil, it can cause infection and every time the tree is watered these pathogens can silently invade the roots and lower trunk tissues. This disease is most active when the soil is not allowed to dry out sufficiently between watering, and especially if the lower trunk area is the last part to dry out.

Foot Rot: is a fungal disease present in many South African soils. Both sour orange and trifoliate orange rootstocks have some resistance to the disease, so it is not a problem unless the tree is planted too low and the bud union is exposed to the soil or is standing in water.

Tristeza: This is a virus disease that kills citrus trees quickly, particularly those growing on sour orange rootstock.

Greening: Greening is prevalent in the relatively cooler, high-lying areas (above 600m). Typical symptoms are yellowing of the leaves and malformed fruit. One side of the fruit does not develop normally and remains smaller, resulting in asymmetrical fruit. The smaller side remains greenish while the rest of the fruit turns orange. The disease is caused by a bacterium for which no chemical treatment is available. It is transmitted by psylla (see Citrus psylla). As greening is usually localised within one or two branches of the tree, it is advisable to completely cut out the infected branches. Saw them off as close to the trunk as possible. If the entire tree is affected, it would be better to remove and replace it.


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info@gardeninginsouthafrica.co.za (Super User) January Tue, 12 Jun 2018 06:56:01 +0000
Good old fashioned cauliflower has seen somewhat of a renaissance in recent years, and it's not hard to understand why. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/good-old-fashioned-cauliflower-has-seen-somewhat-of-a-renaissance-in-recent-years-and-it-s-not-hard-to-understand-why http://www.gardeninginsouthafrica.co.za/index.php/1245-january/good-old-fashioned-cauliflower-has-seen-somewhat-of-a-renaissance-in-recent-years-and-it-s-not-hard-to-understand-why


Cauliflower has been around for a very long time and its history and ancestry can be traced back to the wild cabbage, and its similarities with kale or collards. The ‘cole’ vegetables have a growth habit typical of many members of the family Brassicaceae, with broad, spreading leaves and a branched flowering stem, carrying many individual flowers. They are grown and eaten throughout the world, and include such apparently diverse forms such as cabbage, kale, Brussels sprouts, kohlrabi, broccoli and cauliflower. All of these were, however, domesticated from one ancestral species, the wild cabbage, Brassica oleracea, which is native to the coastal cliffs of the northern Mediterranean and Western Europe, from Greece to the British Isles.

Pliny the Elder (born Gaius Plinius Secundus, AD 23–79) was a Roman author, naturalist and natural philosopher, a naval and army commander of the early Roman Empire, and a friend of Emperor Vespasian. He wrote ‘Natural History,’ a vast encyclopaedia, surveying natural phenomena from cosmology to biology, and medicine to magic. Here, in his descriptions of cultivated plants, he references a plant he called "cyma" stating: "Of all the varieties of cabbage the most pleasant-tasted is cyma." Pliny's descriptions most likely refer to the flowering heads of an earlier cultivated variety of Brassica oleracea. Similar descriptions can also be found in the writings of the Arab botanists Ibn al-'Awwam and Ibn al-Baitar, in the 12th and 13th centuries.

Cauliflowers were apparently introduced into Europe from the Levant or Cyprus at around the end of the fifteenth century. And, although they were introduced to France from Genoa in the 16th century, they did not commonly appear on grand tables until the time of Louis XIV. And so cauliflower became immensely popular in Europe, and well-accepted in Brittany where they were used in sweetbread stews and mushrooms and veal, and later introduced to India in 1822. Cauliflower was first introduced in North America in the late 1600's, and although it was mentioned in American writings as early as the 1800s, it was only in the 1920’s that the cauliflower became commercially available there.

Cauliflower and broccoli are closely related, and the heads which we love to eat are unopened flower buds called "the curd." As many as a dozen cultivars of cauliflower were known one hundred years ago, and today there are even colourful purple and green varieties, although the most common colour you will see is still the white variety.

Significant growers of cauliflower rtoday include: France, India, Italy, The United States and China.

Health Benefits:

Like most fruits and vegetables cauliflower has a long list of nutritional benefits under its belt.  It’s packed with lots of vitamins and minerals, and if you include this vegetable as a regular part of your diet, you can significantly improve your health.

Cauliflower contains high doses of vitamin C, folate and calcium, among other minerals. But most importantly, it has two significant disease-fighters: indole-3-carbinole and sulforaphane. Research has shown that these two work hand in hand to flush toxins out of our bodies. Indole-3-carbinole also helps decrease high levels of oestrogen, thus lowering the risk of tumour growth, especially those located in the breasts and prostate glands.

Cauliflower is also rich in insoluble dietary fibre which helps prevent constipation and haemorrhoids. Because of the glucosinolates and thiocysanates it contains, cauliflower efficiently help the liver in the detoxification process, increasing its ability to neutralize potentially harmful substances. The allicin in cauliflower reduces the risk of strokes and heart problems by maintaining the levels of cholesterol in the body. Yet another nutritional benefit of eating cauliflowers is it has a lipid soluble compound that acts as immune modulator, anti-bacterial and anti-viral compound.

In the Kitchen:

Good old fashioned cauliflower has seen somewhat of a renaissance in recent years, and it's not hard to understand why. This brassica boasts plenty of potential in the kitchen, be it acting as a strong supporting role to main courses in the form of tasty side dishes and salads, or taking the spotlight as the main course.

Cauliflowers are wonderfully versatile, and being pale, they take on the colours of the spices used; and because their flavour is very delicate and unassuming, they can stand alone, or blend beautifully with stronger flavours.
 
Most people associate cauliflower with pickles, delicious cheesy bakes, or thick and creamy cauliflower soups, but recipes for cauliflower are equally varied - from making a carb free pizza base, cauliflower rice or a Persian tortilla, to salads, curries, and even savoury cakes. Whether cauliflower is made into a salad like they do in Sardinia, by combining it with olive oil, garlic and capers, or in a great Indian curry made with potatoes and onions - baked, roasted, fried, steamed, or doused in spices, it remains a star performer in the kitchen, so be adventurous and explore the many inspiring cauliflower recipes online.

Companion Planting:

Companion planting began when gardeners and farmers alike observed that certain plants grew well together, so naturally they continued planting them together for their mutual benefits. Today we need to rediscover this ancient practice – it’s great fun and will reduce the need to spray in the garden.

For example: beans and cauliflower are known to be an ideal combo, celery and cauliflower also work well together, as do onions and cauliflower. Herbs like sage and thyme are also beneficial to cauliflower because their strong scent deters some pests, while their aromatic flowers attract bees and other pollinators.

Other veggies that are recommended for companion planting with cauliflower include: beetroot, broccoli, Brussels sprouts, Swiss chard, spinach, cucumber, corn and radish.

Gardeners also observed that certain plants did not enjoy the company of others. For example, it has been noted that peas stunt the growth of cauliflower, and while onions and cauliflower are a great combo, if you throw beans into the mix, it’s not so great. Strawberries and cauliflower do not make good companions because strawberries are notorious for attracting slugs. Tomatoes are also not good near cauliflower as they need a tremendous amount of nutrition, which will lessen the amount available to the cauliflower.

Cultivation/Propagation:

Because cauliflower plants are sensitive to excessive heat as well as sudden changes in temperature, before hybridisation, cauliflower was always sown from mid to late summer to plant out in autumn when temperatures dropped. Today modern hybrids allow us to extend the growing season, and there are early, mid-season and late varieties available, so choose your cultivars carefully.
 
For the best quality heads cauliflower needs to grow quickly, so prepare the beds extremely well, incorporating lots of compost and a dressing of organic 2:3:2. They like slightly alkaline soil with a pH of 6.5 to 7, and very acid soils will need to be amended with agricultural lime to increase alkalinity.

Seed is best sown into seedling trays, and the seedlings transplanted into bigger containers as soon as the first true leaves appear. Plant them into the garden when they are about 15cm tall, spacing them about 50cm apart, and leaving about 50cm between the rows, depending on the variety.

Cauliflowers need constant moisture to grow well, so water them regularly. They resent competition from weeds, but do not like disturbance around their roots, so don't dig around them, rather pull the weeds out gently by hand. Feed with a balanced organic fertiliser that is high in nitrogen about one month after transplanting and again 3 to 4 weeks later.

Once the heads reach about 7 to 10cm in diameter you can fold the outer leaves over them to protect them from heat and wind damage. Early cultivars can be harvested about 7 to 10 weeks after transplanting; mid-season types take about 12 to 15 weeks; and late varieties can take up to 20 weeks or more to mature. Harvest when they are still firm - do not leave them too long or the heads will become loose and the flavour will diminish.

Problems, Pests & Diseases:

Watch out for aphids, which will cause the leaves to become curled and distorted. Caterpillars, especially the diamond-back and greater cabbage moth caterpillar will eat holes into the leaves and heads, and cutworms can also be a problem. Downy mildew shows as light grey powdery patches on the leaves.

Discoloured heads are caused by sunburn as well as a lack of water.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Tue, 29 May 2018 15:10:07 +0000
Virginian stocks are probably one of the easiest of all plants to grow from seed, thriving in part shade to full sun. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/virginian-stocks-are-probably-one-of-the-easiest-of-all-plants-to-grow-from-seed-thriving-in-part-shade-to-full-sun http://www.gardeninginsouthafrica.co.za/index.php/1245-january/virginian-stocks-are-probably-one-of-the-easiest-of-all-plants-to-grow-from-seed-thriving-in-part-shade-to-full-sun


Virginian Stock 'Enchanted Evening' picture courtesy www.mayford.co.zaThis delightful little annual is hardy and deserves a place in every winter and spring garden. Not only does it flower profusely in delightful shades of pink, rose red, lilac and creamy-white, but it also smells heavenly. It must be the easiest annual to grow and quickly produces small bushes +-20 to 30cm tall and 10 to 15cm wide.

Malcolmia maritima is a popular annual garden plant from the Brassicaceae (Mustard) family and native to South Albania and Greece. It is naturalized in France, the Iberian Peninsula, the Apennine Peninsula and the Balkan Peninsula. Because it occurs in sandy maritime habitats and in waste places, the species name “maritima” refers to this plant’s affinity for the seashore. The genus name “Malcomia” honours William Malcom, the founder of a seed company based in 18th century London.

In the Garden:

Virginian stocks need to be sown in mass to be really effective in the garden, and go perfectly with all spring-time bloomers, especially bulbs. Try sowing them on top of taller bulbs like daffodils or Dutch Iris for a stunning effect. They also pair well with poppies and other taller spring flowers in borders; along pathways, and even in the crevices between paving stones and rocks. Mix it with the night scented stock for brightness and wonderful fragrance.

Because of its rapid growth and appealing fragrance, this plant has been a special favourite of young gardeners for generations. Children love to sow the tiny seeds and watch them grow, so if you see seed packets for sale, grab a few!

Cultivation/Propagation:

Virginian stocks are probably one of the easiest of all plants to grow, thriving in part shade to full sun. They are hardy and grow throughout the country, doing well in coastal gardens; thriving in enriched sandy soil, but adapting to most well-drained garden soils.

Because the seeds are tiny, the hardest part of growing Virginian stocks is scattering the seeds wide enough apart to allow each plant to grow to its full potential. To make sowing easier, add the packet of seed to a bucket full of slightly damp, fine compost and mix together well before sowing. Adding cake flour to the mixture will lighten it so when you spread the soil over the beds, you will be able to see where you have sown. This is especially good when small children are sowing the seeds.
 
Seeds are sown directly into well prepared beds in autumn, as soon as the weather has cooled down significantly, and will take approximately 80 days to flower. Cover the seeds lightly with soil, or gently rake them into the soil. Keep moist until germination, which usually occurs within 7 to 20 days, depending on soil temperatures. Thin the young seedlings out to about 10 to 15cm apart and water regularly until they become established. Despite seed packet warnings to the contrary, if your plants germinate too close together, you can transplant them to a different location, but this is quite time consuming.

Mature plants are fairly drought tolerant, but will appreciate moderate watering in dry weather. For a continuous display of blooms, sow in various places in the garden at two to three-week intervals.  Sowings made in curves, rather than straight lines, often create a more pleasing effect. Remove weeds regularly by hand, as they compete with the seedlings for light and water.

After the flowers fade, slender seed ponds will develop. Wait until the seed heads have fully formed before cutting them off and placing into a large paper bag or envelope. Once completely dry, carefully strip the seeds out of the pods and store in a cool, dry place until next season.

Pests & Diseases:

If grown correctly, Virginian stocks do not suffer from any serious pests or diseases.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Wed, 30 May 2018 09:04:41 +0000
As part of the xeriscape or drought tolerant garden, the stunning Geraldton Wax Plant can’t be beat! http://www.gardeninginsouthafrica.co.za/index.php/1245-january/as-part-of-the-xeriscape-or-drought-tolerant-garden-the-stunning-geraldton-wax-plant-can-t-be-beat http://www.gardeninginsouthafrica.co.za/index.php/1245-january/as-part-of-the-xeriscape-or-drought-tolerant-garden-the-stunning-geraldton-wax-plant-can-t-be-beat


Picture courtesy Ross Funnell - see her flickr pageWhen in full bloom the geraldton wax plant looks like a billowing cloud of cotton candy as the branches sway in the breeze. The needle-thin leaves can be bright to dark-green, depending on the season, and contrast beautifully in texture and colour with the shiny berry-like buds arranged in open sprays along the ends of the stems, and the lush clusters of waxy, star-shaped flowers. If you crush the leaves, they emit a pleasant lemony scent, and the flowers have a sweet, honey fragrance, oozing nectar and attracting butterflies, bees, and other pollinating insects; particularly on warm, late winter or spring days.

The naturally occurring pink or white flowered geraldton wax plant grows quickly into a lovely rounded shape, and is generally clipped into a thick shrub, but if left largely unpruned, the older varieties can reach heights of +- 2.5m with spread of 2m. This hardy shrub has come a long way over the past decade, thanks to improved breeding and hybridisation the geraldton wax plant is extremely popular, and available in colours that range from white to various shades of pink, mauve and wine; sometimes with all the colours on one bush. And, while the traditional form blooms in winter and spring, there are now several hybrids from which to select which will extend the blooming time into early summer. Recently released cultivars are even frost hardy down to -2°C, and delightful new dwarf forms grow beautifully in containers, making them suitable for even the smallest gardens.

Picture courtesy Green Acres Nursery CaliforniaThis gorgeous evergreen belongs to the Myrtle family which contains about 150 genera and 3,300 species of trees and shrubs, notably the Australian tea tree (Leptoscpermum laevigatum), New Zealand tea tree (Leptospermum scoparium), bottlebrush (Callistemon spp.),  and Melaleuca species. Its members are widely distributed in the tropics and characteristically feature leathery leaves with oil glands. Several, like allspice and clove, are useful as spices, and a number of species are economically important for their timber.

Chamelaucium is a genus of about 30 species, all occurring only in south-western Australia, and the gerladton wax plant is endemic to the Shark Bay region of extreme Western Australia, growing wild nowhere else in the world.  It can be found in coastal areas, the edges of swamps, hillsides and plains, thriving in white, grey or yellow sand, over limestone, laterite. Laterite is a clayey soil horizon rich in iron and aluminium oxides, formed by weathering of igneous rocks in moist warm climates. In the wild it varies greatly in height from 50cm to 4m tall, and the immature branches are a smooth greyish-brown, becoming rougher with age. The young twigs can be slightly reddish and are a particularly pretty contrast to the flowers.

Modern hybrids include:

Chantilly Lace (Chamelaucium uncinatum hybrid) is a very prolific flowering variety with masses of buds, opening into dense clusters of pure white blooms with beautiful frilly edges and lime green centres.
 
Dancing Queen (Chamelaucium uncinatum hybrid) is a unique double variety featuring an abundance of blooms, ranging from soft baby pink through to vibrant candy-pink.

Moonlight Delight PBR (Chamelaucium megalopetalum hybrid) produces masses of red buds in mid-winter, followed by an abundance of white blooms with dark crimson centres in early spring.
 
My Sweet 16 (Chamelaucium uncinatum hybrid) has pure white flowers are borne in early spring. The flowers mature to a rich crimson colour, giving the plant a stunning bi-colour appearance of crimson, white and all shades in-between.

Purple Pride (Chamelaucium uncinatum hybrid) produces unique purple blooms that mature to a beautiful dark magenta.

Raspberry Ripple PBR (Chamelaucium uncinatum hybrid) is a beautiful screening plant, which produces masses of dark pink-crimson blooms on thin stems.
 
Sarah's Delight PBR (Chamelaucium uncinatum hybrid) is a tall shrub which produces masses of bright pink flowers with dark crimson centres during late winter and early spring.
 
Strawberry Surprise PBR (Chamelaucium uncinatum hybrid) has stunning pink flowers, which feature a frilly petal formation, and are borne profusely in spring.

Picture courtesy Elizabeth Donoghue - see her flickr pageUses:

The geraldton wax plant is one of Australia's most famous wildflowers and all the rage in the cut flower industry throughout the world because the blooms last extremely well in the vase. It was popular in California as far back as the 1940’s, and was introduced into Israel in the 1970’s. Today it is widely grown in many countries, including South Africa, Chile and Peru.

In the Garden:

As part of the xeriscape or drought tolerant garden, the geraldton waxplant can’t be beat for its consistent bloom, ease of care, and tolerant nature.  It is one of those “plant it and forget it” shrubs, and because it has minimal pest and disease issues, low food and moisture needs, and only requires light pruning, is the perfect low maintenance and water-wise shrub for busy gardeners.

It is well worth growing as a screen or wind break, and will add value to any mixed shrub border, providing colour during the bleakest time of the year when very little is in bloom. The geraldton wax plant is also a must-have for picking gardens.  

The sweet fragrance of the flowers and their rich nectar attract butterflies, bees, and other pollinating insects, providing valuable sustenance when food is scarce. On warm, late winter or spring days, spend time outdoors in the sunshine, clipping some stems for the vase and just inhaling their lovely fragrance – geraldton wax plants are a sure promise that spring is on the way.  

Geraldton wax plant Kings Park, Perth, Western Australia. Picture courtesy Dr Mary Gillham Archive Project - see her flickr pageCultivation/Propagation:

The healthiest plants are produced by mimicking the plants growing conditions in its native Australia. Shark Bay has a semi-arid climate with hot, dry summers and mild winters - the soils are sandy and moisture is sparse, except during the rainy winter season. Therefore, the plant is easy to grow in a Mediterranean climate, and it thrives in the south and south-western Cape, and other mild, frost free regions of South Africa like the KwaZulu-Natal mist belt.  It will tolerate light frost inland if it is planted in a warm, protected position in the garden, and protected until established. The shrub does not tolerate high humidity or overly wet summer conditions.

Full sun is essential for good flowering, and although this shrub prefers sandy, very well-drained soils, be they acid, neutral or alkaline, for quick establishment in very poor soils, amend the soil with plenty of organic matter and till to a depth of about 25cm. If your soil does not have perfect drainage, add sand or other gritty material to enhance percolation, or grow the plant in a raised bed, or containers.

Young plants will need supplemental irrigation as they establish, and although mature plants can withstand fairly long periods of drought, in the garden they will respond well to intermittent watering in the heat of summer. Avoid overwatering as this can cause root rot.

Because its native soil is so low in nutrients, feeding with commercial fertilisers might actually harm the plant, so only use organic mulch around the roots, and apply a light dressing of bone meal in spring. This mulch will slowly release needed nutrients, as well as protect the root zone from cold, and help prevent weeds from growing. Never dig around the roots of this plant as they resent soil disturbance.

An annual pruning when the plant has finished flowering forces tighter, more compact shrubs and helps to keep the centre of the plant open for light and air. Although the geraldton wax plant can take quite harsh pruning, just cutting back the stems by one third will encourage new shoots, which bear the next season’s blooms.

Propagation from seed is difficult but cuttings of firm, current seasons growth will usually strike readily

Problems, Pests & Diseases:

If grown correctly the geraldton wax plant does not suffer from any serious pests or diseases. It is sensitive to root rot fungus (Phytophora sp.) which is one reason why they can be difficult to grow under humid summer conditions. Other than that, scale is the most likely pest that may occur.

Warning:

We could not find any information on the toxicity of this plant.

In Australia, this species is provisionally classified as schedule 1 under the Sewerage Act. Written approval is required prior to planting it in streets or roads, and it may not be planted closer than two metres to any sewer main or connection.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Wed, 23 May 2018 12:36:06 +0000
The Firebush is a voluptuous tropical beauty which produces flowers and berries all year round. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-firebush-is-a-voluptuous-tropical-beauty-which-produces-flowers-and-berries-all-year-round http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-firebush-is-a-voluptuous-tropical-beauty-which-produces-flowers-and-berries-all-year-round


Hamelia patens at Enchanting Floral Gardens of Kula, Maui, Hawaii. Picture courtesy Forest and Kim Starr - see their flickr pageThe firebush is a reliable tropical plant that has found its way into many a landscape because of its  proven drought  and soil tolerance – it can basically grow anywhere!  It is native to the American subtropics and tropics, ranging from the gulf states of Mexico, South Florida, the West Indies, and Central and South America, as far south as Argentina. It is a member of the Rubiaceae family, and other notable members of this family include Ixora, Gardenia, Pentas, Quinine and Coffee.

The gorgeous firebush usually bears both flowers and fruit at the same time, and has no dormant period, growing and producing flowers and berries all year round. Even the flower stems are an attractive red, contrasting beautifully with the bright green leaves; and in autumn the foliage changes to a striking blood-red colour.  The firebush is a soft-stemmed to semi-woody, evergreen perennial shrub which responds well to pruning, but if left unpruned, and under optimal conditions, can grow 4 to 5m tall. Usually it stays much smaller, growing 2.4 to 3m tall and 1.2 to 1.8m wide.

Hamelia patens fruit at Loxahatchee National Wildlife Refuge, Florida. Picture courtesy Forest and Kim Starr - see their flickr pageThe long tubular, reddish-orange or scarlet flowers have dark linear stripes, and hang from the plant in tassel-like, branched clusters. Because their corollas vary greatly in length, they are attractive to a wide range of pollinators. If your plant produces flowers which are more yellow than red, and without stripes, you probably have Hamelia patens var glabra, from Mexico.

The clusters of edible fruits are showy, and each fruit is a juicy berry with many small seeds; ripening from green to yellow, then red, and finally black. The berry is deceptive raw, with an initial sweetness and grape-like texture that yields to a sticky, lingering, slightly bitter but refreshing acidic aftertaste in the back of the mouth, so try one to see if you like them. The fruits are known to contain several active phytochemicals which have antibacterial and antifungal properties, and in Mexico they are made into a fermented drink. The fruit is also relished by birds, dispersing them far and wide.

With all this going for her, who could resist this voluptuous tropical beauty!

Uses:

The Mayans called the firebush “Ix-canan,” meaning guardian of the forest, but it also seems to be a guardian of the people! In Belize the leaves, stems and flowers are boiled in water and used to treat a variety of skin problems including, sores, rashes, wounds, burns, itching, cuts, skin fungus, insect stings and bites. This same liquid is drunk as a tea to relieve menstrual cramps. The Choco Indians in Panama drink a leaf infusion to treat fever and diarrhoea, and the Ingano Indians make a leaf infusion for intestinal parasites. Tribes in Venezuela chew on the leaves to lower body temperature and help prevent a sun or heat stroke. In Brazil the root is used as a diuretic, and the leaves for scabies and headaches. Cubans use the leaves externally for headaches and sores, while a decoction is taken internally for rheumatism. In Mexico it is used externally to stop excessive bleeding, and to help heal wounds.

In laboratory tests on animals, leaf extracts showed analgesic, diuretic, and hypothermic actions. External use showed significant anti-inflammatory activity as well as antibacterial and antifungal properties.

Hamelia patens. Picture courtesy Bob Peterson - see his flickr pageThe industrial use of the plant comes from its high amounts of tannins, and the hard, brown wood also has practical applications.

In the Garden:

The firebush is known as one of the best plants to attract butterflies and sunbirds to the garden, and it will feed our feathered friends for most of the year. And, because it responds well to pruning and can be kept smaller, it is great even for small gardens.
In the tropics it is widely used as a hedge or screen and is often planted in mass plantings and borders, mixed with other shrubs. It is especially attractive mixed with white flowering shrubs and annuals. The firebush is also suitable for planting around the foundations of buildings.

It is very effective if planted as a solitary specimen, and is often used as a small tree in tropical gardens, despite its somewhat scraggy appearance. If it is planted under a small tree, it will develop an almost vine-like habit, growing up into the tree and blooming as it gets closer to the brighter parts of the outer canopy, producing an interesting combination.

The firebush also does well in containers where it can be placed on a patio in summer and brought inside to a sunny location during the winter.

Cultivation/Propagation:

The firebush is a tropical to subtropical plant that is tender to frost. In cold climates it is often grown as a summer annual, where under these short growing conditions it remains a dwarf, about 60cm tall.In frost-free regions it is wonderfully adaptable, growing in hot and dry climates, as well as hot and humid climates, inland and at the coast. Although the firebush thrives in the heat it can sometimes become stressed if it is planted in an unnaturally hot location like up against a very hot wall, or in a pot placed on hot paving. Try to protect it from excessive strong wind, which can cause some leaf browning.

Although the plant thrives in full sun, it will take some shade - in too much shade it can become leggy and will not flower as well. It can tolerate many types of soils from heavy clays to high alkaline as long as it has good drainage. For good results in the garden water regularly during dry spells, but avoid overwatering. To keep the show going, feed every 6 to 8 weeks with a fertiliser for flowering plants.

Since it has no dormant season, pruning can be done at any time - to initiate new growth and more blooms, try to prune at least every year or so. However, a hedge of firebush will need fairly regular clipping, which unfortunately also removes many flowers.

Propagate by softwood cuttings or air-layering in spring. Fresh seed will also germinate readily.

Pests & Diseases:

Organic gardeners will be delighted to know that the firebush does not have many of the pest or disease problems that plague so many other tropical plants. Occasional attacks of scales or mites may require control measures, and the new growth may be attacked by aphids in early spring, but natural predators often rapidly check the invasion.

Warning:

For those who worry about poisonous plants in the landscape, the nontoxic nature of the firebush will come as a welcome relief.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Wed, 16 May 2018 09:26:31 +0000
Boxwood has been modernised and is seen in almost any style of garden today. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/boxwood-has-been-modernised-and-is-seen-in-almost-any-style-of-garden-today http://www.gardeninginsouthafrica.co.za/index.php/1245-january/boxwood-has-been-modernised-and-is-seen-in-almost-any-style-of-garden-today


Buxus macowanii Picture courtesy www.newplant.co.zaBoxwoods are popular with gardeners for their attractive, compact, and low spreading growth habit. Their versatility is renowned and these garden plants can be pruned successfully into just about any shape you desire.

Buxus is a genus of about 70 species in the family Buxaceae, with members widely distributed throughout the temperate counties of the globe, excluding America and Australia. The Common Boxwood (Buxus sempervirens) and the English Boxwood (Buxus microphylla 'Faulkner') are quite well-known in South Africa, but did you know we have our very own Boxwood, which is just as versatile?

Our indigenous boxwood (Buxus macowanii) is endemic to South Africa, meaning that it grows wild nowhere else in the world. It can be found in the Eastern Cape, KwaZulu-Natal, Limpopo, Mpumalanga, and the North West Provinces. In coastal regions it grows in colonies in valleys and forests near the sea, and in coastal dunes, to medium altitudes.

It is a small, very slow-growing tree with an upright habit, producing many stems with drooping branches and deep green leathery leaves, which give off a distinctive scent when wet or bruised. In the wild, once mature, it can reach +-9m tall with a 4m spread; with slender stems about 30cm in diameter, and a greenish bark that is roughish and grooved.

In the garden, however, it is usually kept trimmed to +-25 to 70cm tall and 20 to 30cm wide. Insignificant male and female flowers are borne separately on the same tree from late winter to spring (July to October,) followed by brown capsules holding shiny black seeds, which ripen and split to release them. Although the flowers are inconspicuous, they are fragrant, and pollinated by insects and bees.

Uses:

The wood of this species resembles that of the European Box, with a beautiful yellow colour and a smooth texture. Even though it is hard with a fine grain, the early settlers used it mainly for firewood, but in the late 1800's it was exported to Europe, because of its popularity there for engraving. It was also in demand in the printing trade, as well as for musical instruments, furniture, implements, model making etc.

In the Garden:

Because boxwood responds so well to pruning, is slow growing, and has lovely small leaves, it is perfect for formal hedges and topiaries, parterres, knot gardens, and cloud pruning. And, although it is associated with traditional English box gardens, this is no longer the case, as boxwood has been modernised and is seen in almost any style of garden today.

In cold winter gardens the evergreen foliage provides welcome colour when everything else is a drab brown. Boxwood also provides a great backdrop for small flowering plants or bulbs, and if mass planted, makes a great groundcover for a formal grove of trees. It is also a valuable addition to woodland gardens, fantastic in containers, and a favourite with bonsai enthusiasts.

In the garden, boxwood is usually kept trimmed to +-25 to 70cm tall and 20 to 30cm wide; and nothing beats its lush green foliage for low hedging. Because it is slow growing, once established, boxwood is very low maintenance, requiring minimal clipping.

Cultivation/Propagation:

Boxwood grows well in those regions of the country which receive good summer rainfall, both inland and at the coast. In dry regions regular watering is required to keep it looking its best. It is hardy to moderate frost, but very young plants should be protected in winter until they are established.

Boxwood will grow in full sun, but in very hot regions some shade would be appreciated. It will even grows in almost total shade, but in these conditions growth will be less vigorous. Another great advantage is that the plant will also tolerate dry or wet shade, as long as the soil drains and is not boggy.

It is easy to cultivate in most fertile and well-drained garden soils. Try to purchase reasonably established plants or seedlings, and in order to encourage faster growth prepare the planting holes very well, adding copious amounts of organic matter like compost and a generous dressing of bone meal. Water regularly until the plants are well established. Seasonal mulching and regular feeding during the growing season will also promote growth.

Boxwood can be grown from seeds sown in spring to summer, although germination is very slow. It can also be propagated by cuttings taken in summer, and treated with rooting hormone. Root in a mist unit with heated benches.

Problems, Pests & Diseases:

Suffers from no serious pests or diseases

Warning:

Boxwoods are poisonous to people and to pets because the plants contain steroidal alkaloids. All parts of the plant are poisonous. If the plants come in contact with human skin, it causes minor skin irritation that typically lasts for only a few minutes. If the leaves are eaten, they can cause nausea, vomiting, diarrhoea, dizziness, convulsions and, in extreme cases, respiratory failure.

Pets exhibit similar symptoms to humans. Dogs and cats who have eaten boxwood both suffer from vomiting and diarrhoea. Horses that ingest boxwood plants can develop colic, diarrhoea, seizures and respiratory failure.

Severe poisoning is rare because the tough texture and unpleasant taste limits how much a person is likely to eat. However, the alkaloids in boxwood are dangerous, and if you suspect someone has eaten part of this plant, contact your local poison control centre or family doctor. If the person is having trouble breathing, call 911 immediately.

If you or someone else has an allergic skin reaction to touching boxwood plants, wash the skin immediately with soap and lukewarm water. Wear gloves, a long-sleeved shirt and long pants when planting or trimming boxwood to minimize skin exposure.

For pets that eat boxwood, contact your local veterinarian or an animal poison control centre. The animals may require sedatives and respiratory or heart stimulants to recover from boxwood poisoning.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Sun, 06 May 2018 10:51:06 +0000
The Butterfly Bush will bloom almost continuously from spring to autumn. http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-butterfly-bush-will-bloom-almost-continuously-from-spring-to-autumn http://www.gardeninginsouthafrica.co.za/index.php/1245-january/the-butterfly-bush-will-bloom-almost-continuously-from-spring-to-autumn


The butterfly bush is strikingly beautiful, and because blue remains the most rare and sought-after flower colour for gardens, this plant fits the bill perfectly with its heavenly blue to purple flowers which resemble fanciful butterflies, hence its common name "blue butterfly bush." The fluttering flower panicles sprout from the ends of long arching branches, and each flower has one violet-blue petal and four pale blue ones, framed by long purple anthers which bend elegantly upwards, hence its other common name "blue cat's whiskers".

The plant will bloom almost continuously from spring to autumn, but typically flowers most heavily when the temperatures cool down in autumn. The flowers are a firm favourite with carpenter bees and lure butterflies with their nectar; and the showy, black fleshy fruits are devoured by birds and monkeys.

The dark green evergreen leaves give a wonderful tropical feel to the garden all year round, but when crushed they have a pungent, even rank smell. This smell is what makes the bush repellent to most insects and pests, which in return, reduces the need for spraying in the garden.

The blue butterfly bush remains a highly sought after garden plant for tropical and subtropical gardens alike. However, if you live in the colder regions of the country, and simply have to try one, the good news is Rotheca myricoides will tolerate much colder conditions than most tropical plants, as long as it is planted in a warm and protected position in the garden, or perhaps in a pot which can be moved in winter.

Picture courtesy www.newplant.co.zaIts new Latin name is Rotheca myricoides, and Rotheca is a member of that quite large Lamiaceae or mint family, but until 1998 Rotheca wasn't really a recognized genus until phlogenetic DNA analysis set things straight. The genus comprises of about 30 species, and members include shrubs, perennial herbs, and a few lianas and small trees.
 
The blue butterfly bush is native to tropical Africa and is particularly abundant in Kenya and Uganda, but can also be found wild in Limpopo, Mpumalanga, and KwaZulu-Natal. It is commonly found growing in sheltered groves in rocky places, or along hillsides and river banks, open woodlands and along the margins of evergreen forests, shrubby bushveld, and in coastal bush, from Natal to Transkei, at elevations of up to 1400m.

Because the butterfly bush is a sprawling evergreen with a weak upright growth habit, it is often listed as a vine, although it is far too rangy or bushy to be considered a true vine. In the garden, the plant grows quickly and varies in height and spread. If left un-pruned, and in warm regions, it can reach 2 to 4m tall with an equal spread, but it can easily be pruned at any time to keep it smaller, and amazingly, it will be flowering once again within three to four weeks!

Uses:

The edible fruits are taken as a remedy for skin ailments. The bark has numerous antifungal properties, and is crushed to a powder after which it is used to treat snakebites, reduce bodily swellings and relief indigestion. It is also used to treat colds, chest pains and headaches, as well as being applied to bleeding gums.

The root bark is said to be an effective treatment against fever in cattle, and diarrhoea in calves, and the root itself is said to help improve spleen and liver ailments.

In the Garden:

As it does not have an aggressive root system, the blue butterfly bush is perfect for gardens large or small, and has been cultivated in botanical gardens for almost 100 years. Because blue is an unusual colour for the tropics, it is prized by collectors and considered to be one of the finest blue flowered subtropical plants. It can be pruned to keep it almost any size and is a great candidate for pot culture. Because it grows really quickly, and the flowers are produced in abundance throughout summer and well into autumn, the butterfly bush ideal for small or townhouse gardens, as well as patio planting.

Planted gregariously, the plant looks wonderful in a flowerbed or mixed shrub border, but looks just as lovely when planted as a single specimen. It can also be trimmed to make a sturdy border or screen, and can even be trained as a climber if given support. All this, plus the plants great insect repellent qualities – what more can a gardener ask for!

Cultivation/Propagation:

The butterfly bush grows best in warm, moist, frost-free regions, thriving in the Lowveld and along the KwaZulu-Natal coast. It is not suitable for very dry regions, but if it is watered well during dry periods, will do well in East London, and can be grown successfully in the southern and south-western Cape.

The plant will tolerate much colder conditions than most tropical plants, as long as it is planted in a warm protected position in the garden and the roots are thickly mulched in winter. Usually it is sold as hardy to a minimum of 3°C, but the plant has been known to survive short spells of temperatures as low as -1° and even -5°C outdoors. Always remember, young and unestablished plants are more vulnerable and should always be sheltered from extreme cold and wind.

In cold regions it is deciduous and may even be frozen right back to ground level, but will usually return in spring if the roots are mulched. It makes a wonderful conservatory plant and is often grown in a pot which can be moved indoors in winter.

The butterfly bush is not fussy and will grow in full sun, shade or semi-shade. Partial shade is recommended in areas where summers are very hot. It thrives in organically rich, well-drained soils and should be fed regularly with a fertiliser like 3:1:5. Although established specimens can withstand considerable periods of drought if need be, regular applications of water will keep you plants looking at their best. Reduce watering in winter, especially in cold regions.
 
Pruning can be done at any time to keep the plant in shape, and if it is grown in containers it can be clipped to maintain a rounded shrub. Cutting the old wood back to a pair of buds will improve flowering.

Propagation is by suckers, or semi-hardwood cuttings taken in summer, they root well in perlite. Seeds will usually germinate within 21 to 60 days, but even under good conditions germination may be erratic. Sow in spring or summer at a depth of +-3mm, in a well-drained seed sowing mix; the ideal soil germination temperature is about 22°C.

Caution: In tropical regions, blue butterfly bush is an aggressive plant that tends to spread and may become invasive, so be vigilant about removing any suckers that pop up out of bounds if you don’t want a small forest.

Problems, Pests & Diseases:

The pungent leaves and twigs seem to repel most insects, and this plant is not easily affected by most plant diseases or pests.

Warning:

Some parts of the tree have been recorded as being toxic if ingested, and care should be taken when small children are near.

The information contained within this website is for educational purposes only, recording the traditional uses of specific plants as recorded through history. Always seek advice from a medical practitioner before starting a home treatment programme.

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darlene@gardeninginsouthafrica.co.za (Darlene Roelofsen) January Thu, 03 May 2018 11:48:23 +0000