Thursday, 25 July 2013 00:28

Nemesia, Cape Jewels - Nemesia strumosa

Nemesia Cape Jewels Sundrops Mix. Picture courtesy Ball Horticural CompanyNemesia Cape Jewels Sundrops Mix. Picture courtesy Ball Horticural CompanyPlant drifts of these delightful winter and spring flowering annuals and you will never be able to imagine your garden without them again. They are indigenous to the south-western Cape and are grown for their masses of small snapdragon-like flowers with intense colours, like gold, yellow, orange, rose, pink, peach, red and white. They grow beautifully in containers and make a colourful border plant. Planted in massed displays they make a spectacular show.

Cape Jewels grow quickly to about 25 to 30cm tall and should be spaced about 15 to 20cm apart. They will grow in full sun or light shade. These annuals grow best in regions with mild winters but are semi-hardy to moderate frost if planted in a protected position. They are not suited to hot, humid regions.

Seeds can be sown in trays or directly into well-prepared garden beds in autumn, germinating best in soil temperatures between 18 and 20°C. Do not cover the seed as it requires light to germinate, which will take 3 to 5 days. The plants will take 12 to 15 weeks to flower.

Picture courtesy Jonathan CohenPicture courtesy Jonathan CohenThese unforgettable natives of Chile form dense bushes of feathery foliage which is smothered in a profusion of butterfly-like flowers in winter and spring. They are wonderful cut-flowers with an infinite range of patterns and colours; from pink, blue, violet, lavender, magenta, white, yellow, orange, gold, red and salmon. They make excellent border plants to the winter flower garden and grow exceptionally well in containers, because they bloom best when their roots are restricted. Fill your window boxes and containers with them for a dazzling display.

Picture courtesy Jonathan CohenPicture courtesy Jonathan CohenThese annual plants grow well throughout South Africa, except those areas that experience severe frost. They thrive in cool, yet sunny positions, so plant them in sun to light shade in cool regions and in hotter regions plant them in semi-shade. They must have perfect drainage and good soil that is high in organic matter. Water them regularly in the summer rainfall regions and protect them from strong wind. Hybrid plants vary in height from 20 to 40cm tall.

Seeds are sown in seed trays in late summer and will germinate within about 3 days in ideal soil temperatures between 15 and 22°C. Cover the seeds with vermiculite as they require darkness to germinate. Seedlings should start blooming within 10 to 12 weeks after sowing.

Thursday, 25 July 2013 00:28

Godetia, Satin Flower - Clarkia amoena

Picture courtesy Andrew JorgensenPicture courtesy Andrew JorgensenThe Clarkia family of plants is native to Western - North and South America. They grow wild in California in dry open areas in forests and grasslands. These are popular cool season annuals will flower in late spring and early to mid- summer, depending on when they are sown.

They are excellent cut-flowers; producing satiny cup-shaped blooms in shades of rose to pink and peach, lavender and white; darkening at the base or shading to white or red. Satin Flowers vary in height from 30 to 90cm tall. For the garden, choose a dwarf variety because these plants have a lax growth habit and can flop over easily.

Satin Flowers are easy-to-grow in full sun and are hardy to frost but are not suited to hot humid regions. It is essential that the soil drains very well and is not too fertile. On excessively nutritious soils the plantswill produce too much foliage at the expense of the flowers. Do not overfeed your plants and water them regularly, especially in dry regions. These plants like a bit of crowding and bloom best when planted closely together.

Seeds are best sown directly into garden beds in spring or autumn when the soil temperatures are between 16 and 18°C. Cover the seeds lightly with about 2mm of soil and rake the bed lightly. They will take 7 to 15 days to germinate and will bloom after about 14 to 18 weeks. In hot coastal regions, sow seeds in autumn.

Foxglove. Picture courtesy Bedding Plant Growers AssociationFoxglove. Picture courtesy Bedding Plant Growers AssociationFoxgloves are native to Europe, western and central Asia and north-western Africa, and remain firm favourites for woodland and shady gardens. They are easy-to-grow biennial plants that are planted for their striking flower spikes in spring and summer. Their velvety flowers last long in a vase and have marbled markings in all shades of white, yellow, cream, lavender, rose and red.

The common foxglove can take up to 24 weeks to flower but certain varieties like "Foxy" foxgloves will bloom in spring and summer if planted or sown in autumn.

The varieties vary in height but most of the modern strains are more compact and grow about 60 to 90cm tall and 25 to 40cm wide. The tall spires of flowers provide striking colour and good architectural height to the flower border and are particularly effective in front of dark backgrounds such as those provided by a wall or shrubs.

Foxglove. Picture courtesy Bedding Plant Growers AssociationFoxglove. Picture courtesy Bedding Plant Growers AssociationFoxgloves grow best in regions with high rainfall and must be watered thoroughly during dry spells. They are hardy to frost but are not suited to very humid or hot, dry regions. Foxgloves will grow in semi-shade to sun, but in hot regions plant them in a cool position. They require deep, rich, slightly acid soil that drains well. Add some acid compost or peat to the planting holes. They respond well to regular feeding with a liquid fertiliser.

Protect your plants from strong wind and plant stakes, if required, when you plant out the seedlings, to avoid damage to the roots later. Cutting spent foxglove blooms will encourage repeat blooming. Some gardeners choose to leave the last flower stalks of the season because foxgloves will self-sow in the garden.

Seed can be sown in seedling trays in autumn or spring and germinate best in soil temperatures between 15 and 18°C. Do not cover the seeds but press them gently into the soil and keep moist until germination takes place in about 5 to 10 days.

Canterbury Bells. Picture courtesy Ann SonghurstCanterbury Bells. Picture courtesy Ann SonghurstCondensed Version:

Canterbury bells remind one of a storybook English cottage garden with their tall flower spikes and elegant, bell-shaped flowers, which come in a lovely array of colours, from purple to violet, blue, lavender, pink, and white, and which last extremely long in a vase. These biennial flowering plants take two years to complete their biological lifecycle, and this is a long cultivation period. If grown from seed, the plants can take a whole year or more to flower, but it is sure worth the wait! If you are impatient, you may on occasion see the plants available in nursery pots or trays. Snap them up, as these more established plants will flower sooner. In their first year of growth the plants form a low rosette of green leaves, but the flowering stems can reach +-70 to 80cm in height, making them a perfect background plant for the flower border.  

Canterbury bells thrive in regions with good summer rainfall and are not suited to very hot, dry or humid regions. In South Africa, and the old and trusted Canterbury Bell’s ‘Cup and Saucer’ is still the most readily available variety from seed suppliers. It is generally sown in spring, or in late summer and autumn, and the plants require cold, short days, followed by long days, for flowering. They prefer reasonably cold winter temperatures and are hardy to frost. Although they love full sun they will also grow in light shade, and in hotter regions some midday or afternoon shade would be appreciated. Plant them in good, deep, well-drained soil and water regularly, especially during dry spells.

Germination is easy and will take place within 8 to 14 days, and the tiny seeds are usually sown directly into well-prepared garden beds, but can also be sown into seedling trays. Space them about 30 to 40cm apart in the garden. Cutting out the dead flowers regularly will often encourage a second flush of flowers.

Full Version:

Description, History & Interesting Facts:

Canterbury bells are gorgeous old-fashioned biennials which at one time were widely grown, and which still deserve a place in modern gardens. They remind one of a storybook English cottage garden with their tall flower spikes and elegant, bell-shaped flowers, which come in a lovely array of colours, from purple to violet, blue, lavender, pink, and white, and which last extremely long in a vase.

Campanula medium is native to Southern Europe, but it is naturalized in most European countries and in North America. In its natural habitat it grows on stony, rocky and bushy slopes, at an altitude of 0 to 1,500 metres above sea level.  Canterbury bells are biennial flowering plants which take two years to complete their biological lifecycle. This is a long cultivation period, and if grown from seed, the plants can take a whole year or more to flower, but it is sure worth the wait! And, if they are happy where they are sited Canterbury bells will re-seed themselves in the garden.

If you are impatient, you may on occasion see the plants available in nursery pots or trays. Snap them up, as these more established plants will flower sooner.

In their first year of growth the plants form a low rosette of green leaves, and only in the following spring and early summer will the upright flowering stems appear. Each stem bears loads of large dangling bells, and the flowering stems can reach +-70 to 80cm in height, making them a perfect background plant for the flower border.  

Uses:

Beekeepers sometimes use Canterbury bells for making potently sweet honey.

In the Garden:

Canterbury bells love cooler gardens and when in full bloom they will add grace and elegance to any garden, but are a ‘must-have’ for all country and cottage gardens. They are indispensable for adding vertical interest to the annual and perennial flower garden and wonderful as an under-planting for Roses. Try planting them with delphiniums, hollyhocks and snapdragons around borders and fences for a breath-taking display. They can also add spectacular height to large, mixed container plantings.

Cultivation/Propagation:

Although modern hybrids have been bred which are shorter, with a more compact growth habit, and which do not require cold days to bloom, allowing gardeners to sow seed in spring, summer or autumn, these are not freely available in South Africa, and the old and trusted Canterbury Bells ‘Cup and Saucer’ is still the most readily available variety from seed suppliers.

In South Africa the ‘Cup and Saucer’ variety is generally sown in spring, or in late summer and autumn, to flower in their second year after sowing. The plants require cold, short days, followed by long days, for flowering. So if you want Canterbury bells in your garden every season, you need to sow or plant them out each season.

Canterbury bells prefer reasonably cold winter temperatures and are hardy to frost. They love full sun but will also grow in light shade, and in hotter regions some midday or afternoon shade would be appreciated. Canterbury bells thrive in regions with good summer rainfall and are not suited to very hot, dry or humid regions. Try to plant them in a part of the garden that is protected from strong winds, or the plants will require staking.
 
The tiny seeds are usually sown directly into well-prepared garden beds, but can also be sown into seedling trays. They will germinate best in soil temperatures between 15 and 20°C, and only require minimal covering with soil, as the seeds need light to germinate. Germination is easy and will take place within 8 to 14 days. When the seedlings develop their first true leaves, they must be thinned out to space them about 30 to 40cm apart.

Canterbury bells will tolerate a wide range of soil types as long as they drain well. Plant them in good, deep, well-drained soil and water regularly, especially during dry spells. Cutting out the dead flowers regularly will often encourage a second flush of flowers. However, Canterbury bells will often re-seed themselves in the garden, and you can collect and save the seed for next season. In this case, do not cut back the spent flowers, and allow them to seed themselves, or collect and hang the stems upside-down in a paper bag until the heads are completely dry. Remove the seeds and store in an airtight container until next season.

Problems, Pests & Diseases:

Watch out for snails and slugs. Powdery mildews and rust diseases may be a problem, especially in moist, warm and humid weather. These can be controlled with an appropriate natural fungicide.

Warning:

Campanula medium is listed as non-toxic to humans, dogs, cats and horses.

Thursday, 25 July 2013 00:28

English Daisy - Bellis perennis

Condensed VersionImage by Kerstin Riemer from PixabayImage by Kerstin Riemer from Pixabay:

Throughout winter and spring English daisies produce masses of tightly quilled, single, or double flowers, which stand above the fresh, bright-green leaves. The blooms come in shades of pink, white and rosy red, with cheerful yellow centres, and will bloom continuously for weeks on end. English daisies are neat, compact plants, growing about 15 to 20cm tall, making them superb edging plants for pathways and flower borders, and also for pots.

In South Africa they are grown throughout the country as winter and spring flowering annuals. English daisies are easy to grow, and will adapt to most garden soil types, even heavy clay soils, as long as they are well-drained. For best results, provide a moist, fertile and well-drained soil by preparing the beds well by digging them over and adding organic material like compost, and a dressing of bone meal.

In pots they can be planted together with other compatible bulbs and annuals in good potting soil. All plants growing in pots will require more frequent watering and feeding than those growing in garden beds and many gardeners prefer to use liquid fertilisers to avoid over fertilising or burning their plants. 

In moist soils they love to grow in full sun, but they will take some shade, and in dry winter regions where the days can still get quite hot, some shade will keep them blooming for longer.  Although English daisies love moist soils they have average water needs, so water regularly, but do not overwater.

English daisies are available in seedling trays from garden centres, which is often most convenient and quick for smaller gardens, but they also grow easily from seed sown directly into well prepared beds, or seedling trays, when the soil temperatures are between 15 to 25°C. Cover the seeds lightly (2mm) and if you are sowing into trays, keep them in a cool, bright place until germination takes place. Germination times can vary according to conditions, taking anything from 3 to 20 days. Once the seedlings have their first true leaves they can be thinned out to space them 15 to 20cm apart. Flowering should start about 90 to 100 days after sowing.

To keep them blooming, it is most important to cut out the dead flower heads regularly. If the soil was prepared well, additional feeding may not be necessary, but if you have planted them in garden beds between bulbs or other annuals, English daisies can be fed along with your other winter and spring flowering plants.

Image by Hus16 from PixabayImage by Hus16 from PixabayFull Version:

Description, History & Interesting Facts:

English daisies remain extremely popular garden plants, not only for their charm but also because they are so unfussy and easy to grow. Throughout winter and spring they never fail to delight with their masses of tightly quilled, single, or double flowers, which stand above the fresh, bright-green leaves. The blooms come in shades of pink, white and rosy red, with cheerful yellow centres, and will bloom continuously for weeks on end. English daisies are neat, compact plants, growing about 15 to 20cm tall, making them superb edging plants for pathways and flower borders, and also for pots. Like other daisies, it exhibits the phenomenon of heliotropism, where the flowers follow the position of the sun in the sky.

The English daisy is a common native of western, central and northern Europe, including remote islands such as Faroe Island. It grows in abundance in meadows where it flowers for much of the year, and is also called the "lawn daisy" as it habitually colonises lawns, and is difficult to eradicate by mowing. English daisies are truly so pretty - even the Genus name “bellis” comes from the Latin word “bellus”, meaning pretty; and the garden hybrids we know and love today were developed from this robust and hardy plant. In most temperate regions, including the Americas and Australasia, it has escaped garden cultivation and has become naturalised.

Health benefits:

The medicinal properties of the daisy were recorded as far back as the 16th century, when an English botanist, John Gerard, who had a large herbal garden in London, documented the medicinal properties of daisies in his book “Gerard's Herbal”. Today daisies remain a popular home remedy with a wide range of applications. The herb is mildly anodyne, antispasmodic, antitussive, demulcent, digestive, emollient, expectorant, laxative, ophthalmic, purgative and tonic.

Traditionally daisies are well-known as a “fresh wound herb”, and the flowers and leaves can be used fresh in decoctions, ointments and poultices for treating wounds, bruises, and also boils. Today the plant is harvested when in flower and is used as a homeopathic remedy which is especially indicated for the treatment of bruising.

The fresh or dried flowering heads are used to make an infusion to use as a blood purifier, or to ease complaints of the respiratory tract, including coughs, as well as for the treatment of catarrh, rheumatism, arthritis, liver and kidney disorders. Chewing the fresh leaves is said to be a cure for mouth ulcers.

Always seek advice from a professional before using a plant medicinally.

Uses:

The leaves flowers and buds of this daisy may be used as a potherb. Young leaves can be eaten raw in salads or cooked, although their flavour has been described as somewhat acrid by some people, and pleasantly sour according to others. Flower buds and petals can be eaten raw in sandwiches, soups and salads. Even though the leaves and flowers are edible the plant is mostly used as a medicinal herb

Image by Goran Horvat from PixabayImage by Goran Horvat from PixabayIn the Garden:

English daisies are excellent anywhere in the garden, growing easily in pots and window boxes, and adding some magic to woodland or pebble gardens. They are great bedding plants and striking when planted in flower borders or alongside pathways. They are perfect companions for pansies and violas, or to interplant with winter and spring flowering bulbs, and in large gardens and parks they are often planted in mass together with Dutch Iris, tulips or daffodils. An added bonus is that English daisies will attract butterflies to the garden, providing vital nectar when food is scarce.

Cultivation/Propagation:

In their native habitats English daisies thrive in cool, moist climates, where they are perennial plants which bloom in summer, or even sporadically throughout the year. However, in hot and sunny South Africa they are grown throughout the country as winter and spring flowering annuals. Because they love moisture, these daisies thrive in the winter rainfall regions, and because they do not do well in high heat and humidity, in subtropical regions they are grown during the coolest months. In the cooler mist belt regions of the country blooming will continue into summer.

English daisies are easy to grow, and will adapt to most garden soil types, even heavy clay soils, as long as they are well-drained, growing in acid, neutral and basic (alkaline) soils. For best results, provide a moist, fertile and well-drained soil by preparing the beds well by digging them over and adding organic material like compost, and a dressing of bone meal.

In pots they can be planted together with other compatible bulbs and annuals in good potting soil. All plants growing in pots will require more frequent watering and feeding than those growing in garden beds and many gardeners prefer to use liquid fertilisers to avoid over fertilising or burning their plants.  

In moist soils they love to grow in full sun, but they will take some shade, and in dry winter regions where the days can still get quite hot, some shade will keep them blooming for longer.  Although English daisies love moist soils they have average water needs, so water regularly, but do not overwater.

English daisies are available in seedling trays from garden centres, which is often most convenient and quick for smaller gardens, but they also grow easily from seed sown directly into well prepared beds, or seedling trays, when the soil temperatures are between 15 to 25°C. Cover the seeds lightly (2mm) and if you are sowing into trays, keep them in a cool, bright place until germination takes place. Germination times can vary according to conditions, taking anything from 3 to 20 days. Once the seedlings have their first true leaves they can be thinned out to space them 15 to 20cm apart. Flowering should start about 90 to 100 days after sowing.

To keep them blooming, it is most important to cut out the dead flower heads regularly. If the soil was prepared well, additional feeding may not be necessary, but if you have planted them in garden beds between bulbs or other annuals, English daisies can be fed along with your other winter and spring flowering plants.

If left to self-seed in the garden, the double forms will quickly revert back to ordinary single forms.

Problems, Pests & Diseases:

Generally daisies have no known serious insect or disease problems but may have some problems with root-knot nematodes (galls) and rust.

Warning:

Daisies can cause contact dermatitis in people who are allergic, but generally pose little to no toxicity risk to humans though it is always advisable to supervise babies and small children in the garden.

Some daisies, such as the gerber or Barberton daisy, are not toxic at all while many others contain several toxins that are all dangerous to your pet. The common or English daisy (Bellis perennis) and the poison daisy (Anthemis cotula) are two varieties that are poisonous to dogs, cats and horses. The symptoms of daisy poisoning in animals include contact dermatitis, vomiting, diarrhoea, anorexia, allergic reactions, and prolonged bleeding. If a pet ingests daisies, it is important to call a veterinarian immediately.

These most common daisies contain several poisonous substances including pyrethroids, which are used to make insecticides like flea medication. This can lead to serious problems in your dog if it consumes a large amount of daisies after recently being treated for fleas with medication or shampoo that contains pyrethrins or pyrethroids. Your dog can normally metabolize a small amount of these chemicals which are in the flea treatment, but paired with the natural chemicals in the daisy it can lead to a serious toxic reaction.

Sesquiterpene is another substance found in many daisies that can cause intestinal upset and skin irritation.

Ageratum 'Lilac'Ageratum 'Lilac'Condensed Version:

This little summer annual grows quickly to +-15 to 20cm tall and 15cm wide, and remains an old favourite with gardeners because it blooms nonstop all summer and into autumn, and is available in lovely pastel shades of blue, lavender, pink, and white.

Ageratum grows well in all South Africa’s growing regions and tolerates wind. They will also grow in semi-shade to full sun, and are not fussy about soil as long as it is fertile and well-drained.

Full Version:

Description, History & Interesting Facts:

This little summer annual belongs to the daisy family and is native to Central America and the West Indies. It remains an old favourite with gardeners because its fluffy clusters of flowers bloom nonstop all summer and into autumn.  Flower shades are lovely pastels in blue, lavender, pink, and white, and the hairy, dark green, heart-shaped leaves are also attractive. Ageratum grows quickly, maturing +-15 to 20cm tall and 15cm wide.
 
Ageratum 'White'Ageratum 'White'In the Garden:

Their long-flowering period makes Ageratum ideal for rock gardens, as well as great edging plants and fillers for flower borders. Mixed with other flowering annuals or perennials, they will add texture to the planting, and their soft pastel shades compliment almost any colour scheme. They also look great planted in masses of one colour and are most attractive when paired with silver foliaged plants. Petunias and many other low growing annuals look great next to Ageratum; and contrasting coloured flowers such as Rudbeckia or tall Marigolds, planted behind ageratum create a pleasant colour combination.

Ageratum grows easily in containers, filling in the gaps between other flowers beautifully. Taller growing cultivars make excellent cut flowers; and an added bonus is they attract butterflies to the garden.

Cultivation/Propagation:

Ageratum grows well in all South Africa’s growing regions and tolerates wind. It grows in full sun to semi-shade, but in very hot and dry summer regions the plants will appreciate some shade during the hottest time of the day. They are not fussy about soil as long as it is fertile and well-drained, requiring only regular watering and the removal of weeds for good growth. Removing the old flowers regularly will promote continuous blooming.

Ageratum seeds are sown into seedling trays and require warmth; germinating best in soil temperatures of 25 to 28°C; with a minimum of 21°C. Do not cover ageratum seed as light is needed for germination, which will take 5 to 10 days. The plants will bloom in about 13 to 15 weeks after sowing. Ageratum may also be propagated by cuttings.

Pests & Diseases:

Ageratum is relatively disease and bug resistant, but during hot, dry spells spider mites can attack. To prevent spider mite infestations, mist the plants during dry spells with water, especially underneath the leaves or spray with a suitable insecticide.

In humid conditions powdery mildew can develop and to help prevent this try to water at root level and not overhead, to keep the leaves dry. Also, correct spacing of the plants will ensure a good air flow around the leaves of the plants, helping to prevent mildew outbreaks. If necessary, spray with an appropriate fungicide.

Badly damaged plants can be cut right down and should regrow and flower again.

Warning:

Ageratum does not appear in databases for poisonous plants, but many websites warn it is toxic to cattle. In some people it may cause skin problems if handled a lot, so wear gloves if you are sensitive. 

 

Thursday, 25 July 2013 00:28

Salvia, Scarlet Sage - Salvia splendens

Red Hot Sally Improved Salvia. Picture courtesy Ball Horticultural Company Red Hot Sally Improved Salvia. Picture courtesy Ball Horticultural Company

Red Hot Sally Improved Salvia. Picture courtesy Ball Horticultural Company Red Hot Sally Improved Salvia. Picture courtesy Ball Horticultural Company

These perennial plants are native to Brazil and perform well in hot gardens as long as they can be watered regularly. They will flower all summer and autumn and are available in vibrantly coloured flower spikes from bright red to pink, purple, scarlet, rose, cream and white.

Tall and dwarf varieties are available ranging in height from 15 to 90cm tall. The taller varieties will add accent to flowerbeds and the dwarf varieties make excellent border plants and work well in containers, mixed with other summer flowering annuals.

Salvia is tender to frost and grows easily as a summer annual throughout South Africa, except those very humid regions. It can be plated in full sun or light shade in composted, well-drained soil. In areas with very hot summers plant them where they receive partial shade, especially in the afternoon. Cut your plants back after each flush of flowers and new growth will soon emerge, keeping them blooming continually.

Salvia's are very easy-to-grow and can be sown directly into well-prepared garden beds or seedling trays in spring and summer. Seed will germinate best in soil temperatures between 20 and 25°C. Cover the seed with soil or coarse vermiculite. Germination will take place within 10 to 14 days and the seedlings will bloom about 13 to 15 weeks after sowing.

Carefree Mix Coleus. Picture courtesy Ball Horticural CompanyCarefree Mix Coleus. Picture courtesy Ball Horticural CompanyCondensed Version:

Coleus is cultivated in shady gardens worldwide because it is durable, easy to grow, and amongst the most magnificent foliage plants the plant kingdom has to offer. It can even be grow as an indoor pot plant. Hybridization has produced an almost infinite number of leaf shapes and colour combinations, which include most colours of the spectrum, except true blue. Compact, dwarf varieties have been bred and there is even a trailing coleus. New introductions have also been selected for increased sun and heat tolerance.

Coleus is a good-natured plant that is pretty hard to kill and quite easy to propagate. It grows well throughout South Africa but is not ideally suited to very dry regions, unless it can be watered abundantly. Coleus thrives in subtropical seaside gardens provided it is protected from wind and is watered regularly. In subtropical regions coleus is treated as a short-lived perennial which can be grown all year round, but because it is sensitive to frost, in cold areas it is grown as a summer annual.

Most varieties prefer bright semi-shade and good, moist, well-drained soil. Plants grown in too much sun may wilt, and those grown in too much shade may become leggy. Never allow the soil dry out totally between watering, but do not allow it to become waterlogged either. Although coleus flowers are quite pretty, their true beauty is in their soft, velvety leaves, and most gardeners remove the flowering spikes, and occasionally pinch back the growth tips in order to encourage more bushy leaf growth.

Wizard Series Coleus. Picture courtesy Ball Horticural CompanyWizard Series Coleus. Picture courtesy Ball Horticural CompanyFull Version:

Description, History & Interesting Facts:

Coleus is cultivated in shady gardens worldwide because it is durable, easy to grow, and amongst the most magnificent foliage plants the plant kingdom has to offer. This native of India (including the Himalayas), Sri Lanka, China, Burma, Thailand, Laos, Vietnam, Malaysia, Indonesia and Australia, belongs to the mint family, and can be found at elevations of 100 to 1,600m, where it flowers and fruits throughout the year.

The species was first introduced into Europe from Java in 1851 by a Dutch horticulturalist. At this time, there were few leaf colours and shapes, but by 1877 a wider selection became available when the American William Bull offered seeds at 43 US cents each. Coleus breeding continued into the early 1940s, and by the 1980s the availability of an improved range of cultivars led to coleus becoming the tenth most important bedding crop in the United States.

Hybridization continues to this day and has produced an almost infinite number of leaf shapes and colour combinations, which include most colours of the spectrum, except true blue. Compact, dwarf varieties have been bred and there is even a trailing coleus. New introductions have also been selected for increased sun and heat tolerance.

Watermelon Coleus. Picture courtesy Ball Horticural CompanyWatermelon Coleus. Picture courtesy Ball Horticural CompanyIn the Garden & Home:

Coleus is one of the brightest annuals for semi-shade, livening up any corner of the garden they are planted in. They make a striking display if massed in shady garden beds, and the lower growing dwarf varieties will create a colourful border, while the taller types provide a dramatic background planting.

Coleus is also the perfect container candidate, with the larger varieties making a striking backdrop in oversized mixed containers, and the smaller ones bringing accent and long-lasting colour to any potted planting, so fill your balcony boxes, hanging baskets and any spare containers with them.

The plants are also often grown indoors in a bright, warm room, growing very easily if they are watered well.

Cultivation/Propagation:

Coleus is a good-natured plant that is pretty hard to kill and quite easy to propagate. It grows well throughout South Africa but is not ideally suited to very dry regions, unless it can be watered abundantly. Coleus thrives in subtropical seaside gardens provided it is protected from wind and is watered regularly. In subtropical regions coleus is treated as a short-lived perennial which can be grown all year round, but because it is sensitive to frost, in cold areas it is grown as a summer annual.

Most varieties prefer bright semi-shade and good, moist, well-drained soil. Plants grown in too much sun may wilt, and those grown in too much shade may become leggy. Never allow the soil dry out totally between watering, but do not allow it to become waterlogged either. Although coleus flowers are quite pretty, their true beauty is in their soft, velvety leaves, and most gardeners remove the flowering spikes, and occasionally pinch back the growth tips in order to encourage more bushy leaf growth.

To grow coleus as an indoor pot plant, place your plant in a warm room which provides bright light, including a couple of hours of direct sunlight, if possible. Spindly growth is an indication of insufficient light, and the plant will need to be moved to a brighter position. Coleus requires plenty of water all season and will quickly wilt if allowed to dry out completely. It also loves humidity, so to increase humidity around the plant, stand the pot on top of a drip tray filled with small pebbles and keep the saucer filled with water, but ensure that the pot is not standing in the water. Nip out the growing tips and flowers regularly to keep the plant neat and bushy, and apply a liquid fertiliser about every two weeks throughout the season. Discard the plants at the end of the growing season, as it is better to plant a new, vigorous plant each summer.

Growing a Coleus collection from seed is really quite quick and easy, and the seeds are inexpensive and readily available. They germinate fast and will be showing their first colours in as little as two to three weeks. Another advantage to growing your Coleus this way, is that each packet of seeds will contain many different colours of plants. Seeds can be sown in seedling trays or very well-prepared garden beds, and germinate best in soil temperatures between 21 and 24°C. The seeds need some light to germinate so avoid covering them - simply sprinkle them onto the surface of the soil and press them down. In garden beds, keep the soil uniformly moist, and in seedling trays, to keep humidity high cover the trays with plastic or glass until germination, which normally occurs within 6 to 14 days.  When the seedlings are large enough to handle easily, they should be thinned out and transplanted into individual pots.

Propagating coleus with softwood cuttings is even easier than growing them from seed, and cuttings retain the exact characteristics as the parent plant, enabling you to clone your favourite colours. Cuttings can be taken anytime of the year and root easily in a glass of water or in moist perlite.

Problems, Pests & Diseases:

Coleus is a relatively carefree annual if it is happy where it is growing, but protect young plants from snails and slugs, and watch out for mealybugs, aphids, spider mites and whiteflies, especially if they are grown in an enclosed area like a courtyard, or are growing under a roof or overhang. If the soil does not drain well, and the weather becomes warm and moist, coleus is susceptible to fungal root and stem rot, and downy mildew.

Warning:

Coleus plants are not poisonous to humans and eating or touching them is unlikely to cause illness. However, the plant and sap can cause a reaction in sensitive people, resulting in minor skin irritation, and if eaten, this irritation may occur in the mouth and throat. For this reason it is best to keep them away from children.

They are toxic to pets, and if a dog or cat eats the plant it could cause symptoms such as diarrhoea, vomiting, depression and loss of appetite. If you suspect your pet has eaten this plant, contact your veterinarian immediately.

Thursday, 25 July 2013 00:28

Flowering Tobacco - Nicotiana alata

Nicotiana Nicki. Picture courtesy Ball Horticultural CompanyNicotiana Nicki. Picture courtesy Ball Horticultural CompanyThis family of annuals and perennials is the source of the tobacco leaf. The flowers of the original flowering tobacco are very fragrant and open at night. Modern hybrids remain open all day, but are not always so fragrant or have no fragrance at all. What a pity that many new gardeners may never know the old fashioned flowering tobacco with its heady fragrance.

The modern hybrids are more compact growing and are free flowering for a long period in summer. The petals of the tubular flowers form a beautiful five-pointed star and are available in red, pale yellow, pink, lilac, burgundy, lime, green, and cream and white.

These shady garden classics are essential in cottage gardens. They are excellent cut flowers and attractive in border plantings, because their soft colours mix well with other perennials and annuals. The dwarf varieties are lovely in pots. Modern garden hybrids vary in height from 30 to 45cm tall.

These tough plants tolerate humidity and high temperatures. They grow well throughout South Africa in summer as long as they can be watered regularly and are protected from strong wind. They love to grow in semi-shade but will take some sun in cool regions. Plant them where they will receive full midday and afternoon shade in very hot areas. They love rich, moist, well-drained soil and must be watered regularly. Cutting back the old flower stalks after the first flush of blooms will encourage more flowers.

Nicotiana 'Red'Nicotiana 'Red'

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