Thursday, 25 July 2013 00:28

Marigold - Tagetes erecta

The marigolds we grow in our gardens were actually bred from plants native to North and South America but the first garden plants introduced into Europe came from Northern Africa; hence the confusing names. There are two basic types of marigold; the large-flowered marigold (Tagetes erecta), that is called the African or American marigold and the smaller-flowered French marigold (Tagetes patula). The French marigold is native to Mexico, Nicaragua and Guatemala. The so called "African" marigold is native to the American tropics, where about 50 species occur.

Marigolds are available in all shapes and sizes, from dwarf to tall growing; single or double varieties, all with intense flower shades and mixtures of, orange, yellow, gold, maroon, and mahogany, flame red and light creamy-yellow. Marigolds are good cut-flowers and can be dried. These tough annuals are perfect "learner plants" for demonstrating plant care and the miracle of seed germination to young children.

The marigold is a workhorse of the garden, blooming virtually non-stop for the entire summer. There are dwarf, medium and tall varieties available that vary in height from 20cm to 90cm tall. The dwarf varieties make excellent edging plants and combine beautifully with other annuals in containers. The taller varieties look beautiful mixed with other summer annuals in flowerbeds or in massed plantings of a single variety.

Marigolds are easy-to-grow throughout South Africa. They thrive in hot climates and will adapt to most garden soils, but prefer lightly composted, well-drained soil and full sun. Very rich soil will result in lots of leaves and fewer flowers. Water them regularly but do not overwater. Cut out the dead flowers often to prolong flowering.

Seeds can be sown directly into garden beds in or seedling trays in spring and summer and germinate best in soil temperatures between 22 and 26°C. Cover the seeds lightly with soil or vermiculite. They will germinate within 4 to 7 days and bloom about 10 to 12 weeks after sowing.

Marigold 'Taishan' Picture courtesy www.ballstraathof.co.zaMarigold 'Taishan' Picture courtesy www.ballstraathof.co.za(Marigold 'Taishan') is a dwarf bedding marigold with large double flowers that was featured in the landscapes specially constructed for the 2008 Olympic Games in Beijing, China. The marigolds thrived throughout the high humidity and extraordinary heat of the summer. The tightly petalled blooms are carried on super-strong stems and hold their shape for longer delivering high impact colour. They also tolerate overhead watering. The plant was named after the Taishan Mountains, regarded as preeminent among China's five sacred mountains and means "stability". It is available in gold, yellow orange and a mix of colours.

Thursday, 25 July 2013 00:28

Lobelia - Lobelia erinus

Riviera Mixed Lobelia. Picture courtesy Ball Horticultural Company Riviera Mixed Lobelia. Picture courtesy Ball Horticultural Company Lobelia is indigenous to South Africa, Malawi and Namibia. It has been bred to produce a profusion of tiny flowers in shades of blue, lilac, purple, pink, carmine and white. Some varieties have bronzy foliage and others bright green leaves. These easy-to-grow plants will attract butterflies and deserve a place in every garden, large or small.

They vary slightly in height but the modern varieties are very compact and will grow about 15cm tall. The cascading varieties produce billowing masses of flowers up to 30cm long and are favourites to mix with other plants in hanging baskets and containers. Lobelias are invaluable as edging plants and because of their dainty, compact growth, are perfect combined with bulbs.

Regatta Mixed Lobelia. Picture courtesy Ball Horticultural CompanyRegatta Mixed Lobelia. Picture courtesy Ball Horticultural CompanyLobelia can be grown almost throughout the year in South Africa and are semi-hardy to moderate frost. Water them regularly, especially in dry regions and plant them in good, well-drained soil. They will grow in semi-shade or full sun but in hot regions they do better if planted in semi-shade.

Seeds can be sown in seedling trays in spring or autumn when the soil temperatures are between 21 and 26°C. They need light to germinate, so do not cover them with soil. Germination will take up to one week and the plants will bloom within 9 to 14 weeks, depending on temperatures.


Dianthus 'Jolt' Pink Magic Picture courtesy www.ballstraathof.co.zaDianthus 'Jolt' Pink Magic Picture courtesy www.ballstraathof.co.zaCondensed Version:

Today we are truly spoilt for choice, with gorgeous compact types of the ever popular dianthus chinensis, varying in height from 15 to 25cm, depending on the variety. The blooms of these new hybrids often have frilled or zigzag edges to their petals, and come in outstanding hues of salmon, pink, red, violet and white, and in lovely clear colours as well as bi-colours.

Pinks are tough, long-blooming little annuals which cope well with heat and rain. They do not like high humidity, but otherwise they will grow well throughout most of South Africa, provided they can be watered regularly. Regular watering is especially important in summer, if they are grown in the winter rainfall regions. Pinks are also hardy to frost, making them very versatile in inland gardens, and one of those annuals which can be planted all year round.

Plant them in full sun, or at least 6 hours of sun a day, and although dianthus are adaptable to most fertile, well drained garden soils, they thrive in slightly alkaline soil, so if your soil is acid, treat it with agricultural lime before planting. When transplanting seedlings be very careful to plant the same level they were growing in the pots - planting too deep will almost certainly cause the death of the plants. Correct spacing of your plants is also essential to ensure good air flow around the leaves, so check the label to find the growers recommendations.

After they have had their first flush of flowers, if you cut back your plants by about one third and remove the dead flowers, they will be blooming again in no time. Fertilising every 4 to 6 weeks with any feeder for flowering plants will also encourage repeat flowering through the season. At the end of the season, be it winter or summer, the little plants will lose their vigour and will need replacing.

Buying trays of the various types of dianthus available to transplant is probably the most convenient for most gardeners, however, if you wish to grow dianthus chinensis from seeds, sow them in spring or autumn, and cover very lightly with soil after sowing. The best soil germination temperatures are between 18 and 24°C, and under these temperatures, and if the seed is fresh, germination should take place within 3 to 7 days, and the plants should be blooming within 12 to 18 weeks.

Older varieties of Sweet William (Dianthus barbatus) are usually treated as a garden biennial that is sown in the first year to flower the following year, but newer varieties have been bred to flower in the first year from seed. Seed that is sown in late spring and summer will take about 15 to 17 weeks to flower and seed sown in late summer and autumn will take 17 to 22 weeks to flower. Use well-drained seed compost and germinate in soil temperatures between 18 and 24°C. Do not cover the seed, as light is required for germination. Seal the tray inside a polythene bag until after germination, which usually takes 7 to 21 days.

Dianthus 'Pink Kisses' Picture courtesy www.ballstraathof.co.zaDianthus 'Pink Kisses' Picture courtesy www.ballstraathof.co.zaFull Version:

Description, History & Interesting Facts:

Dianthus is an old-fashioned flower which has always been favoured by gardeners because it is a tough little annual with the most irresistible flowers. It is also easy to grow and can be planted almost throughout the year in South Africa, because it not only withstands our summer heat and heavy rainfall, but is also frost hardy.

But did you know that dianthus is one of the earliest cultivated flowers and has been revered for centuries? The name is derived from a combination of the Greek words “Dios” (god) and “Anthos” (flower) or “Flower of the Gods.” Dianthus were so important to the ancient Greeks and Romans that they were added to celebratory garlands, and were often featured in the ornate friezes adorning important buildings.

This small Dianthus chinensis plant always fascinated plant breeders, but it was a little disappointing because it had a very short blooming season, but luckily for gardeners, in 1971 a breeder learned how to grow forms that did not set seed and which therefore had a longer flowering season. And so the love affair between dianthus, gardeners and breeders alike continues, and today we are truly spoilt for choice, with gorgeous compact types varying in height from 15 to 25cm, depending on the variety.

The blooms of these new garden hybrids often have frilled or zigzag edges to their petals, and come in outstanding hues of salmon, pink, red, violet and white, and in lovely clear colours as well as bi-colours. And, because dianthus belongs to the family of plants which includes carnations, like carnations, they are characterized by their spicy fragrance, with notes of cinnamon and clove. Unfortunately, due to hybridisation for other characteristics, they often lose their scent, so if you specifically want a highly scented variety, sniff the flowers first before selecting your favourites. With a little TLC these little plants can bloom all season long.

Considering their colour range, it’s easy to see why Dianthus chinensis picked up the common name “pinks,” and as a side note, the verb “to pink” was popularized in the fifteenth century, and means “to finish an edge with a scalloped, notched, or other ornamental pattern” - just like the edges of these pretty pinks. 

Dianthus 'Diamond Mix' Picture courtesy www.ballstraathof.co.zaDianthus 'Diamond Mix' Picture courtesy www.ballstraathof.co.zaDianthus is a genus of flowering plants in the family Caryophyllaceae, a name derived from the Greek for clove tree, and a reference to their clove scented flowers. This family is commonly called the “pink family” or “carnation family” and consists of 300 species, most of which are native to Europe and Asia, with a few indigenous to North Africa, and one alpine species which is native to the arctic regions of North America.

South Africa even has a beautiful one called “Dianthus mooiensis” which is available from indigenous growers online. 

Pinks (Dianthus chinensis) is a species of dianthus which has a large distribution area from eastern Europe to East Asia, which includes not only China and the northern parts of India, but also south-eastern Russia, Mongolia, Kazakhstan, and Korea. It grows wild in a wide variety of habitats including sandy forest margins, dry hillsides and summits, grasslands and scrubby mountain slopes, rocky ravines, meadows and alongside streams.

Flowers within this genus include 3 extremely popular garden favourites: Carnations (Dianthus caryophyllus), Pinks (Dianthus chinensis), and Sweet William (Dianthus barbatus).

Sweet William (Dianthus barbatus) is native to Europe and the Mediterranean and remains an old-fashioned summer flowering favourite for the garden. It is prized for its sweetly-scented, single or double, long- lasting cut-flowers, in lovely shades of pink, rose, red, purple and white, and sometimes bicoloured with fringed petals. There are both tall and dwarf varieties available which vary in height from 15 to 60cm tall. The flowers of Sweet William are edible and used to decorate cakes and salads. 

Sweet William Picture courtesy Karina Bjork Sweet William Picture courtesy Karina BjorkIn the Garden:

Pinks are excellent value for money, and their ease of growth, combined with their long flowering season, make them one of the most attractive summer or winter flowering plants to liven-up flower borders and rockeries. They are essential in mixed containers like hanging baskets or window boxes, are long time cottage garden favourites, a ‘must have’ for scented gardens, and particularly lovely when mixed with roses, scented geraniums and lavender.

Summer or winter flowering annuals, including pansies, violas, petunias, snapdragons, stocks, salvia, delphiniums, verbena, and zinnia will compliment dianthus beautifully, and their colours also look wonderful against the soft grey leaves of groundcovers like lamb’s ear.  

When it comes to companion plants for pinks, look for plants that share the same growing conditions. For example, dianthus prefers bright sunlight and well-drained, dry soil, so plants that like shade and moist soil aren’t good companion plants for them.

Like their close relative the carnation, pinks are excellent cut flowers, and even though their stems are much shorter than carnations, they are delightful in small bouquets.

Dianthus 'Diana' White Picture courtesy www.ballstraathof.co.zaDianthus 'Diana' White Picture courtesy www.ballstraathof.co.zaCultivation/Propagation:

Pinks are tough and long-blooming, coping well with heat and rain. They do not like high humidity, and provided they can be watered regularly, they will grow well throughout most of South Africa. Regular watering is especially important in summer, and especially if they are grown in the winter rainfall regions. Pinks are also hardy to frost, making them very versatile in inland gardens, and one of those annuals which can be planted all year round.

Plant them in full sun, or at least 6 hours of sun a day, and although dianthus are adaptable to most fertile, well drained garden soils, they thrive in slightly alkaline soil, so if your soil is acid, treat it with agricultural lime before planting. When transplanting seedlings be very careful to plant the same level they were growing in the pots - planting too deep will almost certainly cause the death of the plants. Correct spacing of your plants is also essential to ensure good air flow around the leaves, so check the label to find the growers recommendations.

After they have had their first flush of flowers, if you cut back your plants by about one third and remove the dead flowers, they will be blooming again in no time. Fertilising every 4 to 6 weeks with any feeder for flowering plants will also encourage repeat flowering through the season. At the end of the season, be it winter or summer, the little plants will lose their vigour and will need replacing.

Buying trays of seedlings to transplant is probably the most convenient for most gardeners, however, if you wish to grow Dianthus chinensis from seeds, sow them in spring or autumn, and cover very lightly with soil after sowing. The best soil germination temperatures are between 18 and 24°C, and under these temperatures, and if the seed is fresh, germination should take place within 3 to 7 days, and the plants should be blooming within 12 to 18 weeks.

Older varieties of Sweet William (Dianthus barbatus) are usually treated as a garden biennial that is sown in the first year to flower the following year, but newer varieties have been bred to flower in the first year from seed. Seed that is sown in late spring and summer will take about 15 to 17 weeks to flower and seed sown in late summer and autumn will take 17 to 22 weeks to flower. Use well-drained seed compost and germinate in soil temperatures between 18 and 24°C. Do not cover the seed, as light is required for germination. Seal the tray inside a polythene bag until after germination, which usually takes 7 to 21 days.

Dianthus Mixed. Picture courtesy www.lifeisagarden.co.zaDianthus Mixed. Picture courtesy www.lifeisagarden.co.zaProblems, Pests & Diseases:

New species are bred for disease resistance, and are mostly problem-free, and if you cater to their needs, they will be well prepared to combat attack.

Powdery mildew forms on the leaves in warm, humid conditions. Provide proper ventilation and destroy any affected plants, or treat with a fungicide. Dianthus also does not like ‘wet feet’ so ensure that your soil has perfect drainage. 

Rust can be prevented by providing adequate ventilation. Remove and dispose of any leaves infected with rusty or brownish marks on them, or treat with an application of copper oxychloride. Infected plant matter should be thrown in the garbage, not added to the compost pile.

Aphids sometimes feed on the stems and may be easily controlled with a sharp spray of water from a hose, or with ladybugs which serve as a natural predator.

Carnation flies sometimes lay their eggs on the foliage, burrowing into the leaves and creating pale “tunnels.” Companion planting with garlic or spraying with a garlic tea will eliminate flies and their larvae.

Warning:

Dianthus chinensis has low severity poison characteristics, and can cause low toxicity only if eaten. If skin irritation occurs it is minor or lasting only for a few minutes.

Celosia Glow Mixed. Picture courtesy Ball Horticultural CompanyCelosia Glow Mixed. Picture courtesy Ball Horticultural CompanyCondensed Version:

Celosias, with their bright feathery blooms that last from spring through autumn, right up till the first hard frost, are finally getting the recognition they deserve. Their vivid hues practically glow in the garden and come in fiery shades of red, gold, yellow, cream, orange, rose, deep magenta, and pink. They are almost indestructible and remain the same shape and texture even during severe storms. Celosia also loves the basking in full sun and is easy to grow, with countless gorgeous hybrids to choose from, ranging in height from 20 to 75cm tall, making them perfect for any garden situation.

Plant or sow directly into garden beds when the soil is warm, as Celosias cannot tolerate cold temperatures and need warmth to germinate. They will adapt to most garden soils, but for best results plant in soil that is rich in organic matter, and which drains well.  Water regularly during dry spells but do not overwater, because if the beds remain soggy for long, the plants become susceptible to fungal diseases. In garden beds apply a balanced fertiliser every six weeks, and feed potted specimens regularly with a liquid fertiliser for flowering plants.

Full Version:

Description, History & Interesting Facts:

Celosias, with their bright feathery blooms that last from spring through autumn, right up till the first hard frost, are finally getting the recognition they deserve. Their vivid hues practically glow in the garden and come in fiery shades of red, gold, yellow, cream, orange, rose, deep magenta, and pink. Even the generic name derived from the Ancient Greek word k?leos, means "burning," referring to the flame-like flower heads.

Amazingly, although these soft feathery plumes seem delicate and are soft to the touch, they are almost indestructible and remain the same shape and texture even during severe storms. Celosia also loves the basking in full sun and is easy to grow, with countless gorgeous hybrids to choose from, ranging in height from 20 to 75cm tall, making them perfect for any garden situation.

Celosia is a small family of edible and ornamental plants in the amaranth family, Amaranthaceae. The exact geographic origins of celosia in the wild are unknown, although speculations include the dry slopes of Africa and India as well as dry stony regions of both North and South America. The various species are commonly known collectively as "wool flowers, or, if the flower heads are crested by fasciation, "cockscombs". The plants are well known in East Africa’s highlands and are used under their Swahili name, "mfungu".

In the Victorian language of flowers, celosias signified humour, warmth, and silliness, and it is not hard to see why. Watch as folks, especially children, walk by a planting of celosia, and you will likely see them break out with a smile. Celosias quirky flowers certainly beg for attention and you also won’t be able to resist reaching down to touch their amazingly soft plumes.

In the Garden & Home:

Tall growing celosias will bring vertical interest and long-lasting colour to sunny plantings, and even the small varieties will add interest to flower borders. They look stunning in baskets, containers and window boxes, whether planted alone or mixed with other summer flowering annuals or perennials. Celosias look particularly lovely when combined with dahlias, Zinnias and Marigolds, and snap up any varieties you may find with red foliage to heat up the display even more!

The flowers of this species are excellent cut flowers for fresh arrangements, and because they keep their colour for a long time, are dried and preserved for indoor decoration. Celosia is also a popular indoor pot plant in many regions of the world.

Cultivation/Propagation:

These tropical plants are grown as summer annuals in cold regions, and in subtropical climates they can be grown year round. They are easy to grow from seed, and young plants are readily available at garden centres in spring and summer. They love full sun, thrive in heat and humidity, and even during unpredictable summer weather you can count on them to come through heat and some drought unscathed.

Celosias are very versatile and will adapt to most garden soils, even clay, but for best results plant in soil that is rich in organic matter, and which drains well. Although the plants can tolerate short periods of drought they grow much better when the soil remains slightly moist. However, do not overwater, because if the beds remain soggy for long, the plants become susceptible to fungal diseases.

If they are planted in good, rich soil and a good general purpose fertiliser is added to the beds before planting, celosias may require no further fertilisation to keep them blooming all season, but if growth slows down, apply a balanced fertiliser every six weeks. Feed potted specimens regularly with a liquid fertiliser for flowering plants.

Celosias cannot tolerate cold temperatures and to germinate well they need warm soil temperatures. Sow them directly into garden beds, or into seedling trays, when the soil temperatures are between 24 and 25°C. Cover the seed lightly with soil or perlite and keep moist until germination, which should occur within 2 to 7 days. The plants will start flowering about 15 to 18 weeks after sowing.

Problems, Pests & Diseases:

Common pests and diseases that infect celosia plants are aphids and spider mites which can be treated with a suitable insecticide.

Poorly-drained soils and overwatering makes them susceptible to root rot, and fungal leaf spot diseases may also occur. Spray with an organic pesticide and fungicide if necessary, and find a better spot to grow them next season.

Warning:

Celosia plumosa is not listed as toxic to humans, and is non-toxic to dogs, cats and horses.

Nierembergia PurpleNierembergia PurpleCondensed Version:

The cupflower is grown as a summer flowering annual in South Africa for its neat, dense, spreading mound of attractive fern-like foliage and a profusion of delicate, paper thin, star-shaped flowers in shades of purple, blue, lavender or white, each with a deep purple centre, blooming on and off from late spring through summer and into autumn. Because of their low and spreading growth habit, +- 15 to 20cm tall and 20 to 30cm wide, cupflowers work well everywhere, from rockeries to hanging baskets.

Cupflowers grow well throughout most of the country, and can take the heat, but in cooler summer regions they will bloom almost continuously all summer. They do well in seaside gardens, but prefer a dry heat and are not suited to humid areas of the country. In the winter rainfall regions they will need regular watering throughout the growing season; and in extremely hot regions cupflowers will often stop flowering in the height of the summer heat, resuming when the weather cools down again.

Although cupflowers love full sun they will take some semi-shade, especially in the hotter regions. They will adapt to most garden soils which drain well, but do add some compost to the beds before sowing or planting. In very hot regions, if the plants stop producing flowers in the heat of summer, give them a light pruning, mulch the roots with compost or other organic matter and keep them watered. When they start producing buds again later in summer, feed with a fertiliser for flowering plants, and you will be rewarded with another wonderful flush of blooms.

Nierembergia WhiteNierembergia WhiteFull Version:

Description, History & Interesting Facts:

Nierembergia is a family of 20 or more herbaceous South American perennials that are related to petunias, tomatoes, and potatoes. The cupflower is a native of Brazil and Argentina, and although perennial, is generally grown as a summer flowering annual in South Africa. It forms a dense, spreading mound of attractive fern-like foliage and a profusion of delicate, paper thin, star-shaped flowers in shades of purple, blue, lavender or white, each with a deep purple centre.  Blooming on and off from late spring through summer and into autumn, cupflowers are really rewarding to grow, and caring for them is a piece of cake!

Because of their low and spreading growth habit, +- 15 to 20cm tall and 20 to 30cm wide, cupflowers work well everywhere, from rockeries to hanging baskets, and their long blooming season makes them one of the most rewarding and economical summer flowers for gardeners with a tight budget.

In the Garden:

Cupflowers work well in a rockery, cascading over a wall, as a border plant, or for lining walkways and pathways with ease. They are great filler plants for those gaps between slowpoke plants with tall spikes like snapdragons and flowering tobacco. They also look fantastic when combined with thicker textured plants like the Purple Coneflower (Echinacea), Irises, or the Pineapple Flower (Eucomis). However, this lovely little summer bloomer really shines in containers or hanging baskets, which allow the flowers and feathery foliage to trail over the side of the container. Mixed with other summer bloomers, cupflowers will complement most other colour schemes, adding contrast and months of colour to combination planters. An added bonus is they will attract beneficial pollinators like bees to the garden and are a magnet for butterflies.

Cultivation/Propagation:

Cupflowers are planted as summer annuals in South Africa, and although they grow well throughout most of the country, and can take the heat, in cooler summer regions they will bloom almost continuously all summer. They do well in seaside gardens, but prefer a dry heat and are not suited to humid areas of the country. In the winter rainfall regions they will need regular watering throughout the growing season; and in extremely hot regions cupflowers will often stop flowering in the height of the summer heat, resuming when the weather cools down again.

Although cupflowers love full sun they will take some semi-shade, and in hotter regions some respite from the blazing midday sun would be an advantage. They will adapt to most garden soils which drain well, but do add some compost to the beds before sowing or planting. If your soil is fertile, the plants will need no further feeding, but when the buds appear, a feeding with a fertiliser for flowering plants will do no harm. Pinch the growing tips off the young plants to encourage them to bush, and remove the dead flowers regularly to keep them blooming for longer. In very hot regions, if the plants stop producing flowers in the heat of summer, give them a light pruning, mulch the roots with compost or other organic matter and keep them watered. When they start producing buds again later in summer, feed with a fertiliser for flowering plants, and you will be rewarded with another wonderful flush of blooms.

You may find cupflower bedding plants for sale at your local garden centre in spring and summer, but the plant is easily grown from seed, so if you spot some, grab a couple of packets to sow directly into garden beds a week or two before the last expected frost in spring, or start them indoors six to eight weeks ahead of time. Seeds will germinate within 14 to 20 days, depending on soil temperatures; ideal temperatures are between 21 and 25°C. Cover the seeds very lightly with soil but do not exclude light, and place the trays in a warm, well-lit position. Cupflowers will bloom within about 15 to 18 weeks after sowing.

Cupflowers flowers can also be propagated by taking cuttings in summer, and these can be overwintered and planted out into the garden again in spring for very early blooms.

Problems, Pests & Diseases:

Cupflowers suffer from no serious insect or disease problems, but watch out for slugs, snails and aphids. The plants are susceptible to powdery mildew, which shows as powdery splotches of white or grey on the leaves and stems of the plants. Although powdery mildew is unattractive, it is rarely fatal. However, it does stress the plant and severe or repetitive infections will weaken the plant, so treat with a suitable fungicide. Dampness or high humidity, coupled with crowded plantings and poor air circulation around the plants encourages its development.

Warning:

In our research we did not find much on the toxicity of Nierembergia, but the plant Nierembergia hippomanica var. violacea has been incriminated in field outbreaks of neurotoxicity in calves in the Free State Province. It is also suspected of being toxic to horses and poultry.

Also, Nierembergia hippomanica has become naturalised in several parts of South Africa, and during a recent SAPIA (South African Petroleum Industry Association) survey it was seen at the Mountain Zebra National Park where it has escaped from cultivation.

Vinca 'Storm' OrchidVinca 'Storm' OrchidThis perennial, as its common name implies is native to Madagascar and is one of the most reliable plants to grow in the blazing sun. It loves the heat and does not like to be overwatered, making it the perfect choice for water-wise gardens. It produces charming phlox-like flowers in many shades of pink, carmine, blush, coral, peach, mauve burgundy and white, from spring to the first frosts. In temperate regions it will bloom all year round.

In addition to being a wonderful plant for beds and borders it can also be grown in containers, window boxes, and hanging baskets. Plant breeders have introduced dwarf, compact varieties as well as those with a trailing growth habit. The varieties Vinca 'Storm' PinkVinca 'Storm' Pinkrange in height from 20 to 60cm tall. Strains have also been bred that are more tolerant of cooler, wetter climates.

This is a low-maintenance, relatively trouble-free plant that is easy-to-grow as long as it is planted in full sun and in very well-drained soil. It does not perform well in wet, poorly-drained soils and does not like cool weather. In wet soils and cool spring weather the leaves will turn a sickly yellow- green. Poorly drained soil can cause root-rot. In cold regions allow the soil temperatures to warm up nicely before planting out in spring. Do not over fertilise these plants or they will produce lots of leaf growth at the expense Vinca 'Storm RedVinca 'Storm Redof the flowers. The removal of faded flowers or deadheading is not necessary.

Vinca seeds need warmth and germinate best in soil temperatures between 21 and 26°C. They also need darkness to germinate, so cover them with vermiculite. The seeds will take 7 to 21 days to germinate. Once they have been transplanted place them in a cooler place and slowly harden them off to full sun before transplanting them into the garden. They will bloom about 10 to 14 weeks after sowing. Many varieties will self-seed themselves in the garden.

Thursday, 25 July 2013 00:28

Snapdragon - Antirrhinum majus

Luminaire Sugarplum Trailing Snapdragon. Picture courtesy Ball Horticultural CompanyLuminaire Sugarplum Trailing Snapdragon. Picture courtesy Ball Horticultural Company


Antirrhinum Mix. Picture courtesy Bedding Plant Growers AssociationAntirrhinum Mix. Picture courtesy Bedding Plant Growers Association

Snapdragons are native to the Mediterranean region, from Morocco and Portugal to France, Turkey and Syria. They remain firm favourites with gardeners because they can be grown throughout the year in South Africa and are available in dwarf, tall and even trailing varieties. They have a delightful scent, last well in a vase and are available in nearly every available flower colour, or bicolour, including red, bronze, yellow, orange, pink, purple, cream and white.

They have long been a favourite garden play-thing of children. The flowers resemble faces with two large lips and it is fun to gently squeeze the sides of the flower to see them open like a mouth and then snap shut again.

Snapdragons have a narrow, upright growth habit that adds vertical contrast to pots and garden beds. They are wonderful in the mixed flower border and the dwarf varieties make excellent edging plants. Plant them in window boxes, hanging baskets and containers of all sizes. Mix them with other flowering annuals for a long-lasting effect. Snapdragons are charming if planted in cottage gardens and combine well with winter and spring flowering bulbs.

These perennial plants are grown as annuals in South Africa. They love full sun and are hardy to frost. Protect the tall varieties from strong wind and water them regularly. Plant them into well-prepared beds that drain well.

They vary in height from 15cm to 1m tall. When the plants are about 10cm tall, pinch off the stem tips to encourage shorter but more abundant flower spikes. Cutting the flowers regularly for the vase will force plants to produce additional stems that will bloom later in the season.Deadheading will prolong their flowering period. Cut them right back when they stop flowering, mulch with compost; feed and water them thoroughly and they will grow again to produce one more set of blooms.

Snapdragons are easy-to-grow from seed and can be sown almost throughout the year in South Africa. The best soil germination temperatures are between 18 and 24°C in autumn or spring. Cover the seeds lightly with sifted soil or vermiculite and place your trays in bright light. They will take 4 to 7 days to germinate and should flower in about 14 weeks.

Thursday, 25 July 2013 00:28

Columbine - Aquilegia hybrids

Songbird Robin Aquilegia. Picture courtesy Ball Horticultural CompanySongbird Robin Aquilegia. Picture courtesy Ball Horticultural CompanyCondensed Version:

These beautiful perennial plants remain firm favourites to plant in shade gardens because they start flowering in late spring and continue into summer. The attractive fern-like leaves are a perfect foil for the exotic- looking flowers, which are available in shades of pink, red, blue, violet, rose and burgundy, white, yellow and orange. There are very compact, dwarf varieties available that grow 13 to 20 cm tall, and the larger varieties vary from 40 to 75cm tall.

Aquilegias grow in semi-shade to sun and are hardy to frost, but are not suited to humid or very dry regions. They adapt to most garden soils but do best in rich, well-composted soil that drains well. Water your plants regularly during hot, dry spells, and protect them from strong wind. Removing the spent flowering stems regularly will encourage additional blooms, as well as feeding monthly with a liquid fertiliser.

Modern hybrids will flower within 28 to 34 weeks after sowing seed, whereas older varieties will take two seasons to mature and flower, so if you are impatient, purchase trays of seedlings or even instant colour pots, where the plants are already in bloom.

Full Version:

Description, History & Interesting Facts:

Aquilegia is a large family of plants that are found in meadows and woodlands and at higher altitudes throughout the Northern Hemisphere, and many species are native to North America in particular. These beautiful perennial plants remain firm favourites to plant in shade gardens because they start flowering in late spring and continue into summer. The attractive fern-like leaves are a perfect foil for the exotic- looking flowers, which are available in shades of pink, red, blue, violet, rose and burgundy, white, yellow and orange. There are very compact, dwarf varieties available that grow 13 to 20 cm tall, and the larger varieties vary from 40 to 75cm tall.

Aquilegia F1HybridR Picture courtesy www.nuleaf.co.zaAquilegia F1HybridR Picture courtesy www.nuleaf.co.zaIn the Garden:

Aquilegia is essential for all shade gardens and particularly suited to cottage gardens. Its delicate, ferny foliage complements perennials with larger leaves, doing beautifully in mixed flower borders, or behind spring flowering bulbs for a delicate contrast. Aquilegias also give a beautiful effect if planted in drifts in woodland gardens, and the dwarf varieties are perfect for planting in patio pots and window boxes.

Aquilegias also have excellent potential as cut flowers, lasting up to 2 weeks in a vase. An added bonus is that they are also very popular with bees and butterflies, attracting them to the garden like magnets.
 
Cultivation/Propagation:

Columbines grow in semi-shade to sun and are hardy to frost, but are not suited to humid or very dry regions. They’re also hardy at high altitudes, thriving at 2,000 meters, with some varieties even liking it at 3,000 meters above sea level!

They adapt to most garden soils but do best in rich, well-composted soil that drains well. Water your plants regularly during hot, dry spells, and protect them from strong wind. Removing the spent flowering stems regularly will encourage additional blooms, as well as feeding monthly with a liquid fertiliser.

Modern hybrids will flower within 28 to 34 weeks after sowing seed, whereas older varieties will take two seasons to mature and flower, so if you are impatient, purchase trays of seedlings or even instant colour pots, where the plants are already in bloom.

Seed can be sown in late summer and autumn or in spring and early summer, when the temperatures are between 20 and 24°C, and can take up to two weeks to germinate. Chilling them in the refrigerator for a few weeks before sowing will speed up germination. Cover the seeds lightly with soil as they require darkness to germinate.

If cared for correctly, and if left undisturbed, these perennials can last for several years before fading out, but the plants readily set seed and will self-sow in the garden. You can also save seeds to sow next season. Keep in mind that if you have planted several varieties in the garden, they will commonly cross-pollinate, so you may see new colours and combinations emerging in the garden - quite exciting!

Columbine Songbird Bluebird Improved. Picture courtesy Ball Horticultural CompanyColumbine Songbird Bluebird Improved. Picture courtesy Ball Horticultural CompanyPests & Diseases:

Aquilegia is susceptible to several foliar diseases like powdery mildew. Powdery Mildew is a fungus which is easily identified by a white/grey powdery substance sitting on leaves, and can be treated with fungicidal sprays. To help prevent foliar diseases, ensure that there is good air circulation around the plants.

One of the most common insect problems is a serpentine type leaf miner. Leaf miners are insect larvae that live inside the leaves and eat the internal cell layers, showing light tan, wiggly lines running through the leaves. This insect is not fatal to the plant and is mostly just an aesthetic problem. The best ‘treatment’ is to cut off and dispose of any affected plant part. Do not put the infected leaves on the compost heap, or you can spread the problem throughout the garden. Once they have finished blooming you can even cut the plant right down to the ground. Most often the new growth will be leaf-miner free.  Leaf miner can be treated with horticultural oils and very specific pesticides – most contact pesticides cannot reach them, as they are inside the leaf itself.

Warning:
    
Interestingly, the flowers of Columbines were consumed by Native Americans as a condiment, and the taste is sweet and safe in moderation. And, although they also used small doses of this plant to treat ulcers, medicinal use is avoided as an incorrect dosage could be fatal. The roots and seeds are highly toxic and if these parts are ingested it can cause severe gastroenteritis and heart palpitations.

Thursday, 25 July 2013 00:28

Delphinium - Delphinium

Delphinium 'Guardian Lavender' Picture courtesy www.ballstraathof.co.zaDelphinium 'Guardian Lavender' Picture courtesy www.ballstraathof.co.zaCondensed Version:

There are numerous delphinium species and cultivars, and some are charming dwarfs while others are majestically tall. They will be available at garden centres when it is the correct time to plant or sow them, and for the average gardener it would be much less hassle to simply purchase a tray or two to see how they do in your garden. Pop them into well prepared beds, treat them right, and you will be rewarded in spades. Larkspurs are also unforgettable and much easier to grow than delphiniums, from seed sown directly into garden beds.

It is not difficult to imagine why Delphiniums are known as the “queen of the border” and in Afrikaans “pronkridderspoor”. In early spring and summer tall spikes of densely packed flowers arise from a basal rosette of leaves, displaying exquisite shades of soft lavender, light to deep blue, violet-purple, white and rose pink blossoms, with contrasting white or dark centres.

Delphiniums are excellent cut flowers, and if they are grouped together in the garden, the taller varieties add drama and vertical accent to mixed flower beds, and the dwarf forms are equally graceful and charming in their own way, making wonderful bedding and border plants for gardens small and large.  All types can also be grown successfully in pots, where they also look best if grouped together.

Delphiniums are hardy to frost, and newer cultivars have been bred to be more tolerant of heat and humidity, but generally perennial delphiniums do best in regions with relatively cool and moist summers, and often struggle in very hot and dry summer regions. For this reason, in South Africa delphiniums are normally treated as early spring and summer flowering annuals, with some blooming in winter. They are best sown or planted out into the garden in late summer and autumn, or in early spring. In cooler regions they are treated as short-lived perennials, which can continue to produce flowers for another season or two.

Larkspurs are also unforgettable and much easier to grow than delphiniums, and varieties grow from 30 to 90cm tall, and are happy in full sun or light shade. Unlike delphiniums they are low maintenance, and an added bonus is that they will happily reseed themselves in the garden year after year.

Larkspurs are easy to grow from seed, and are grown not only for their abundance of gorgeous cut flowers, but also for their light, airy foliage which lends a soft fern-like effect. Their airy stalks of sky-blue to navy-blue blossoms are sought-after by gardeners because blue is a hard to find colour in the flower world. Other flower colours include shades of purple, red, pink, and white. Flowers can be single or double, and will add a gracefulness and invaluable colour to the garden in spring and early summer.

Delphinium 'Casablanca' Picture courtesy www.ballstraathof.co.zaDelphinium 'Casablanca' Picture courtesy www.ballstraathof.co.zaThese classic cottage garden flowers deserve a place in modern garden settings because they can be used in so many innovative ways, looking just as good in a modern garden inter planted with ornamental ‘grass-like’ plants, as they are in a cottage garden. They are unforgettable if planted in large drifts, or combined with other perennials and annuals in borders and containers.

Although larkspurs are easier to grow than delphiniums, their cultivation requirements are basically the same.

Delphiniums can be propagated from seed or stem cuttings; however, the fastest way to get a burst of colour in the garden is to transplant mature plants growing in seedling trays or small bags from your local garden centre in early spring or in late summer and autumn.

Delphiniums require extra care and maintenance in the garden, and are normally treated as annuals or short-lived perennials in South Africa. And although new cultivars are more tolerant of heat and humidity, generally they prefer cooler climates. They are hardy to frost and will grow in sun to light shade. They require very fertile, well-drained soil which has been dug over deeply, so add lots of good quality compost, a light dressing of bone meal and some 2:3:2 or 3:1:5 to the beds, and water it in lightly a day or two before planting.

The tall varieties are not suited to very windy sites and need to be staked, so when you plant out your seedlings, plant stakes for support at the same time. Shorter types will be fine without any additional help. To help prevent fungal diseases ensure that the plants are correctly spaced. Because there are endless cultivars of various heights and spreads, space your selection according to the instructions on the seed packets or seedling trays.

Delphiniums need consistent moisture, especially when they are in bloom, so ensure that the plants stay evenly moist, but they must also not be kept constantly soggy. Once they start to make buds and additional feeding feed with a liquid or granular fertiliser for flowers can be applied. While they are blooming, regularly remove the faded flower spikes back to the nearest new lateral flower spike.

In cooler summer regions many of the perennials can be encouraged to re-bloom again in late summer by cutting them back when blooming has ceased in summer. Cut the plants back to the leaves at the base of the plants, mulch with compost and feed with a liquid or granular fertiliser for flowers. By cutting them back right down to the basal leaves once again in winter and watering moderately in winter, new growth will often re-appear again in spring.

Delphinium 'Magic Fountains Mixed' Picture courtesy www.nuleaf.co.zaDelphinium 'Magic Fountains Mixed' Picture courtesy www.nuleaf.co.zaFull Version:

Description, History & Interesting Facts:

There are numerous delphinium species and cultivars, and some are charming dwarfs while others are majestically tall. They will be available at garden centres when it is the correct time to plant or sow them, and for the average gardener it would be much less hassle to simply purchase a tray or two to see how they do in your garden. Pop them into well prepared beds, treat them right, and you will be rewarded in spades. Larkspurs are also unforgettable and much easier to grow than delphiniums, from seed sown directly into garden beds.

In late summer and autumn garden centres start bringing in their winter and spring flower selection, but sadly because of COVID-19 restrictions both growers and retailers have been forced to cut down and don’t have the broad selection of plants we were accustomed to having. However, growers and gardeners have an innate ability to adapt and improvise, and gardening has not been cancelled. In fact the pandemic has resulted in a surge of brand new gardeners, and garden centres are open for business and are doing everything they can to roll with the changing tide. All the most popular winter flowering seedling will be available, but some like delphiniums and larkspurs may be harder to find in your region, so get your orders in early, and if you do see them, grab a couple for your garden, you won’t be disappointed.

Delphinium 'Guardian Blue'  Picture courtesy www.ballstraathof.co.zaDelphinium 'Guardian Blue' Picture courtesy www.ballstraathof.co.zaThere is an incredible amount of confusion about the various species of delphinium, and the real origins of today's garden hybrids are extremely complex and probably unknown. There is also great confusion between Delphinium and Larkspur. They both belong to the Ranunculaceae family, which includes: Ranunculus, Delphinium, Consolida and Thalictrum. Delphinium and Consolida (Larkspur) are very closely related, and collectively they are known by the common name "Larkspur". Based on DNA analysis, some researchers suggest including Consolida in the Delphinium genus, so for this reason we have included them here together.

Larkspur and delphinium also look very similar, but a few differences set these two plants apart. Firstly delphinium tends to be a perennial species, whereas larkspur is a true annual. The foliage also differs, with the foliage of larkspur being finer textured than that of delphinium. When it comes to blooms, delphinium flowers tend to be much larger than larkspur, and are densely born, while the spikes of larkspur flowers tend to be held more loosely.

With those few exceptions, general plant care and maintenance is basically the same, however Larkspurs are much easier and less fussy to grow than Delphiniums.

Delphinium

It is not difficult to imagine why Delphiniums are known as the “queen of the border” and in Afrikaans “pronkridderspoor”. In early spring and summer, tall spikes of densely packed flowers arise from a basal rosette of leaves, displaying exquisite shades of soft lavender, light to deep blue, violet-purple, white and rose pink blossoms, with contrasting white or dark centres. However, the rich, clear blues are especially prized by gardeners because blue flowers are in short supply in nature.

Delphinium 'Diamonds Blue' Picture courtesy www.ballstraathof.co.zaDelphinium 'Diamonds Blue' Picture courtesy www.ballstraathof.co.zaDelphiniums are excellent cut flowers, and if they are grouped together in the garden, the taller varieties add drama and vertical accent to mixed flower beds, and the dwarf forms are equally graceful and charming in their own way, making wonderful bedding and border plants for gardens small and large. They can also be grown successfully in pots, where they also look best if grouped together.

Delphinium has about 300 species and its distribution ranges throughout the temperate regions of the northern hemisphere, from the Mediterranean region to Japan, Siberia, and North America. The centre of origin and diversity of delphinium are the eastern Himalayas and southwest China, where over 40% of all the species are found. They occur in a wide variety of habitats, from high alpine zones to the low-lands. Some are tiny, growing only 10cm tall, while others are majestic, reaching up to 2m tall. Delphinium species are annuals, biennials, and perennials, and generally the perennial species are more common in cold and wet climates, and at high altitudes, and the annual and biennial species are more typical for the Mediterranean areas.

Delphiniums are hardy to frost, and newer cultivars have been bred to be more tolerant of heat and humidity, but generally perennial delphiniums do best in regions with relatively cool and moist summers, and often struggle in very hot and dry summer regions. For this reason, in South Africa delphiniums are normally treated as early spring and summer flowering annuals, with some blooming in winter. They are best sown or planted out into the garden in late summer and autumn, or in early spring. In cooler regions they are treated as short-lived perennials, which can continue to produce flowers for another season or two.

Like most recognized ornamental plants, these perennials have become a subject of hybridization, and most of the delphinium cultivars that adorn our gardens today are hybrids. Many plant breeders crossed different delphinium species around the world and came up with better-performing varieties, as well as delphinium varieties exhibiting new flower colours. Victor Lemoine, the 19th-century French flower breeder who is famous for his work with lilacs, led the early hybridization of Delphinium elatum, from which many of today’s popular cultivars are derived.

Delphinium cultorum 'Guardian' White. Picture courtesy Ball StraathofDelphinium cultorum 'Guardian' White. Picture courtesy Ball StraathofDelphinium elatum 'Guardian Series'

This series of F1 hybrids is one of the early bloomers, and is considered a breeding breakthrough, providing blooms a full six weeks before the open-pollinated cultivars, and producing an abundance of flowers on strong stems in spring to early summer, and they can often be coaxed to re-bloom in late summer and autumn. These beauties are available in mixed and single colours which include royal-blue, shades of lavender, and white. The plants love sun to light shade and reach about 76 to 99cm tall when in bloom, and should be spaced 30 to 36cm apart. The guardian series is excellent for adding drama to garden beds and containers, and is an excellent cut flower. This perennial is best when used as an annual and does not tolerate extreme summer temperatures. Because the Guardian Series is shorter, if planted in a position where it is protected from strong winds, it is less likely to need staking.

Garden varieties with single colours such as: Guardian Blue, Guardian Lavender, and Guardian White are available in South Africa.

Delphinium elatum ‘Magic Fountain Series’

The Magic Fountain series is a perfect delphinium for smaller gardens or where space is at a premium. It may be a shorter variety but it produces elegant, densely packed flower spikes, 75 to 90cm tall, with large, semi-double florets in delightful shades of blue, pink, purple, and lavender, with white petals in the centre of the flowers that resemble a ‘white bee’. Magic Fountains Series delphiniums are perennials that mature in their second year from seed, and flowering times can vary, depending on when they are sown. For this reason, try to buy seedlings or small plants from a garden centre. Generally they are treated as annuals which flower in spring and early summer, but if they are cut back after blooming they can produce another flush in autumn. The plants love full sun but will take light shade, and seedlings should be spaced about 40cm apart. Magic Fountains Series is great in garden beds and if planted in groups makes a great impact, but it can look just as good grouped together in pots.

Delphinium cultorum 'Magic Fountains Lilac Pink White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Lilac Pink White Bee' Picture courtesy Ball StraathofLook out for: ‘Magic Fountains Mix’; ‘Cherry Blossom White Bee’; ‘Lavender White Bee’; ‘Lilac Pink White Bee’; ‘Mid Blue White Bee’; ‘Sky Blue White Bee’; and ‘Pure White’.

Delphinium grandiflorum ‘Pacific Giants'

The Pacific Giants are also referred to as the ‘’Pacific Hybrids’ series or ‘Pacific Strain’. Pacific Giants is well-known in South Africa and this beautiful perennial grows 1.2 to 1.8 in height, and in spring and summer, when in full bloom, it forms long, dense columnar spikes of single to double florets, in a wide range of colours, including: blue, white, purple, lavender, and pink. The grandiflora group has a higher heat tolerance than other delphiniums, and is more suitable for drier areas. However, in hotter parts of South Africa it is usually grown as an annual, but in cooler regions can be treated as a perennial.

Pacific Giants are available in seedling trays or seed packets, and the best temperatures for seed germination are 15 to 20°C.  Sow at a depth of 3mm, keep moist but not soggy, and germination should occur within 14 to 21 days. Once the seedlings have their first true leaves they can be spaced about 30 to 50cm apart. Blooming should begin within about 100 to 150 days.

Delphinium cultorum 'Magic Fountains Lavender White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Lavender White Bee' Picture courtesy Ball StraathofDelphinium grandiflorum ‘Blue Butterfly’

Blue Butterfly is one of the most well-known dwarf delphinium cultivars, which only grows about 40cm tall with an equal spread. And although it is a short lived perennial, or biannual, it is most often grown as an annual.  It is also easy to grow from seed sown in spring, or in late summer and autumn, and is more heat tolerant than most delphiniums. It blooms in its first year from seed, producing masses of small azure-blue flowers in spring and early to mid-summer, and with a bit of coaxing, can flower again in autumn. Blue Butterfly is an outstanding bedding variety which also grows well in pots. 

Delphinium grandiflorum ‘Diamonds Blue’

Diamonds Blue forms a low, bushy mound of lacy green leaves, growing about 60cm tall with a spread of 30cm. The plant bear loose sprays of single, electric-blue flowers with purple tips, and is often sold for winter blooms, but because it is more tolerant of hot, humid summer climates than other delphiniums, it can continue to bloom into spring and early summer, and if cut back after blooming, may continue into late summer. Diamonds Blue is Ideal for containers, the rock garden and for edging the sunny border. Remove faded flower heads regularly to encourage repeat blooming. Although it is a short-lived perennial, it is usually treated as an annual and if it is happy in its environment, will often self-sow in the garden.

Delphinium cultorum 'Magic Fountains Sky Blue White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Sky Blue White Bee' Picture courtesy Ball StraathofDelphinium x belladonna 'Casablanca White'

This lovely cultivar bears single, snow-white flowers on strong stems about 75 to 90cm tall. Flowering is in early spring and summer, and although it is a perennial, it is often treated as an annual. If the plants are cut back after blooming, they will often re-bloom later in summer and autumn. Belladonna cultivars have a good resistance to mildew infection, and are therefore said to have superior performance in hot, humid climates. The members of this group are multi-branching, and the flower spikes are not as densely packed as in other varieties. They are also shorter-growing, making them perfect for smaller gardens and containers.

Delphinium x belladonna ‘Sky Blue’

Sky Blue is a dark, sky-blue cultivar which produces numerous flowering stalks on strong stems, about 75 to 90cm tall. Flowering is in early summer and spring, and although it is a perennial, it is often treated as an annual. If the plants are cut back after blooming, they will often re-bloom later in summer and autumn. Belladonna cultivars have a good resistance to mildew infection, and are therefore said to have superior performance in hot, humid climates. The members of this group are multi-branching, and the flower spikes are not as densely packed as in other varieties. They are also shorter-growing, making them perfect for smaller gardens and containers.

Delphinium x belladonna ‘Blue Donna’

Blue Donna grows about 90cm tall with a spread of 30cm, and bears single bell-like, light-blue flowers. Flowering is in spring and early summer, and although it is a perennial, it is often treated as an annual. If the plants are cut back after blooming, they will often re-bloom later in summer and autumn. Belladonna cultivars have a good resistance to mildew infection, and are therefore said to have superior performance in hot, humid climates. The members of this group are multi-branching, and the flower spikes are not as densely packed as in other varieties. They are also shorter-growing, making them perfect for smaller gardens and containers.

Delphinium x belladonna 'Blue Donna' Picture courtesy Ball StraathofDelphinium x belladonna 'Blue Donna' Picture courtesy Ball StraathofDelphinium x belladonna ‘Bellamosum'

Bellamosum bears single, deep indigo-blue flowers in spring and early summer, on stems about 1m tall, and although it is a perennial, it is often treated as an annual. If the plants are cut back after blooming, they will often re-bloom later in summer and autumn. Belladonna cultivars have a good resistance to mildew infection, and are therefore said to have superior performance in hot, humid climates. The members of this group are multi-branching, and the flower spikes are not as densely packed as in other varieties. They are also shorter-growing, making them perfect for smaller gardens and containers.

Delphinium Cultivation:

Although delphiniums are propagated from seed, or stem cuttings, the fastest way to get a burst of colour in the garden is to transplant mature plants growing in seedling trays or small bags from your local garden centre. These won’t take very long to flower and can be planted out in early spring or in late summer and autumn.

Delphiniums are very showy but require extra care and maintenance in the garden, but if their basic needs are met, they are well worth growing. Delphiniums are normally treated as annuals or short-lived perennials in South Africa. And although new cultivars are more tolerant of heat and humidity, generally they prefer cooler climates. They are hardy to frost and will grow in sun to semi-shade, doing very well in full morning sun and afternoon shade. Make sure that they get at least 4 hours of full sun a day or they will not flower well.

They require well-drained soil which has been dug over deeply, at least 30 to 50cm deep, and filled with  really good soil with high fertility, so add lots of good quality compost, a light dressing of bone meal and some 2:3:2 or 3:1:5 to the beds, and water it in lightly a day or two before planting. If you have heavy clay-like soil, add compost and some washed river sand to the planting site to improve drainage.

The tall varieties are not suited to very windy sites and need to be staked, so when you plant out your seedlings, plant stakes for support at the same time. Shorter types will be fine without any additional help. To help prevent fungal diseases ensure that the plants are correctly spaced. Because there are endless varieties of various heights and spreads, space your selection according to the instructions on the seed packets or seedling trays.

Delphiniums need consistent moisture, especially when they are in bloom, so ensure that the plants stay evenly moist, but they must also not be kept constantly soggy. If they remain too dry for too long, the plants can become stunted with poor bud set.

Once they start to make buds and additional feeding feed with a liquid or granular fertiliser for flowers can be applied. While they are blooming, regularly remove the faded flower spikes back to the nearest new lateral flower spike.

In cooler summer regions many of the perennials can be encouraged to re-bloom again in late summer and autumn by cutting them back when blooming has ceased in summer. Cut the plants back to the leaves at the base of the plants, mulch with compost and feed with a liquid or granular fertiliser for flowers. By cutting them back right down to the basal leaves once again in winter, and watering moderately thereafter, new growth will often re-appear again in spring.

Delphinium consolida 'Summer Colors' Picture courtesy Ball StraathofDelphinium consolida 'Summer Colors' Picture courtesy Ball StraathofLarkspur (Consolida)

Larkspur is a relatively small genus of about 40 species, and the species consists of annual flowering plants native to the Mediterranean region, Asia, and Western Europe. The regions of greatest diversity of the species are the Irano-Turanian region and the Mediterranean basin.

Larkspurs are easy to grow from seed, and are grown not only for their abundance of gorgeous cut flowers, but also for their foliage which lends a soft fern-like effect. Their airy stalks of sky-blue to navy-blue blossoms are sought-after by gardeners because blue is a hard to find colour in the flower world, and larkspurs have it in spades. Other flower colours include shades of purple, pink, red and white. Flowers can be single or double, and will add a gracefulness and invaluable colour to the garden in spring and early summer.

These classic cottage garden flowers deserve a place in modern garden settings because they can be used in so many innovative ways, looking just as good in a modern garden inter planted with ornamental ‘grass-like’ plants, as they are in a cottage garden. They are unforgettable if planted in large drifts, or combined with other perennials and annuals in borders and containers.

Larkspurs varieties grow from 30 to 90cm tall, and are happy in full sun but can handle a small amount of shade. Unlike delphiniums they are low maintenance, and an added bonus is that they will happily reseed themselves in the garden year after year. In fact, they are so prolific that, under ideal conditions they could become invasive, so diligently pull them up where they are not wanted, and before they flower, and dispose of them in the compost heap. Remove spent flower spikes regularly to prolong flowering.

Delphinium consolida 'Summer Nights' Picture courtesy Ball StraathofDelphinium consolida 'Summer Nights' Picture courtesy Ball StraathofLarkspurs are extremely unfussy plants which are very hardy to frost and freezing temperatures, and because they resent disturbance of their long tap roots, they are great to sow directly into garden beds in late summer and autumn. Larkspur seeds need a cold period before they germinate, and this can be done by chilling your seeds for up to two weeks in the refrigerator before planting. You can just pop the packet into the refrigerator or you can put the seeds in a zip-lock bag with a handful of damp perlite, which will provide moisture for the seeds. Once you sow them in the garden, they should germinate within 2 to 3 weeks, and flowering begins about 20 weeks from germination.

Larkspurs will adapt to most garden soils, they prefer fertile, well-drained soils, so make sure that the beds are thoroughly dug over, with lots of added compost, a dusting of bone meal, and a dressing with balanced fertilisers like 2:3:2 or 3:1:5, and once they start to make buds and additional feeding can be applied. Remove spent flower spikes regularly to prolong flowering.

Although they don’t like to stay wet for long periods of time, larkspurs do need consistent moisture, so ensure that the plants stay evenly moist, especially when they are in bloom. If they remain too dry for too long, the plants can become stunted with poor bud set.

Sadly larkspurs seeds are not as freely available in South Africa as they used to be, but Larkspur ‘Regal Strain Mixed’ is available in seed packets from Kirchhoffs. Seeds can also be ordered online from overseas suppliers to South Africa.

Garden centres will often stock Delphinium consolida hybrids in seedling trays, at the best planting time for your specific region, so enquire about availability and the correct time to plant, and start preparing your planting beds.

Delphinium consolida 'Summer Stars' Picture courtesy Ball StraathofDelphinium consolida 'Summer Stars' Picture courtesy Ball StraathofDelphinium consolida 'Summer Series'

Look out for a beautiful hybrid series of Delphinium consolida, called “Delphinium Summer”. The name is a bit confusing because it is often grown to flower in winter and early spring, but because this series has a better heat tolerance than many other delphiniums, it can continue to bloom into summer, and if cut back after blooming, may continue into late summer and autumn. If it is happy in its environment, it will often self-sow in the garden.

This garden variety is well worth growing because of its dwarf, compact growth habit, about 30cm tall with an equal spread, and its masses of flowers in attractive mixed or single colours, making it perfect for bedding and borders, as well as containers. It is also a lovely cut flower for smaller bouquets.

‘Summer Colours’ is a mixture of royal-blue to pale blue, pink, and white flowers; ‘Summer Nights’ is a magnificent navy-blue; and ‘Summer Stars’ is pure white.

Pests & Diseases:

Delphiniums are susceptible to powdery mildew if the weather is misty or humid, and should be well-spaced to help prevent infections.

Delphiniums require well-drained soil for optimal growth, and waterlogging is a serious problem which can cause the roots to decay. Once root rot sets in, chances are the plant cannot be saved. It is therefore best to provide good drainage from the start.

Black leaf spots are caused by small mites called cyclamen mites, which devour parts of the leaves and stems of the delphinium plant. Application of insecticidal soap twice a week is quite effective in removal of these pests and others like plant lice, and aphids which cause the leaves to curl.

Warning:

All members of the Delphinium genus are toxic to humans and animals. Ingestion leads to nausea, vomiting, abdominal pain and muscular spasms. If fatal, death is usually due to respiratory collapse or cardiac arrest. Largely because there is nothing about the plant to encourage ingestion, it is rated Category 'C' by the Horticultural Trades Association as having the lowest potential for harm to humans. However, it is always wise to supervise small children in the garden, and to discourage pets from chewing on garden plants.

Thursday, 25 July 2013 00:28

Zinnia - Zinnia elegans

Zinnia 'Magellan' mix. Picture courtesy BallStraathofZinnia 'Magellan' mix. Picture courtesy BallStraathofCondensed Version:

Zinnias bloom from late spring until the first frosts, and are available in white, cream, green, yellow, apricot, orange, red, bronze, crimson, purple, pink, and lilac. The flowers come in a number of shapes, including ‘beehive’, ‘button’, and ‘cactus’, and there are double, semi-double and dahlia-like ‘pompon’ flowered varieties. The plants also come in different heights that range from dwarfs not exceeding 15cm in height to cut flower beauties that grow 90cm tall.

Zinnias grow best in climates with long, hot, dry summers, and grow well throughout South Africa because they are extremely heat tolerant and water-wise. However, in humid regions they are susceptible to fungal diseases, but new and improved varieties like 'Zahara' and ‘Profusion’ are available that are more resistant to rust and other fungal diseases.

As soon as the weather warms up in spring, they are sown directly into garden beds, where they will germinate within four to seven days, and the plants should start flowering within 8 to 10 weeks after sowing. If you prefer to buy zinnia plants in seedling trays from your garden centre, to ease their transition in the garden, prune the plants back by one-third.

Zinnias are adaptable to most soil conditions, but the ideal soil will be well-drained and fairly rich in organic matter. Full sun is essential for them to bloom at their fullest potential. Sow as per the instructions on your seed packet and cover with soil as they require darkness to germinate. Keep the beds moist but not soggy until germination takes place. Once established they are quite drought tolerant and should be watered judiciously. To maximize growth and blooms fertilise lightly with any good product for flowering plants.

Zinnia 'Profusion' mix. Picture courtesy BallStraathofZinnia 'Profusion' mix. Picture courtesy BallStraathofFull Version:

Description, History & Interesting Facts:

Zinnias are cheerful summer flowers which are ideal for hot and dry summer gardens, blooming in nearly every bright colour imaginable.  They must be one of the easiest summer flowers to grow from seeds sown directly into garden beds, where they grow quickly and reliably, making them most economical and a great choice for beginner gardeners and old pros alike.  

These natives of Mexico are so beloved by gardeners that breeders are continually coming up with new and exciting cultivars for the garden, and they are now available in a diversity of flower colours and a variety of sizes and flower shapes, some with flower heads up to 15cm across. They bloom from late spring until the first hard frosts, and are available in white, cream, green, yellow, apricot, orange, red, bronze, crimson, purple, pink, and lilac.

Zinnia flowers come in a number of shapes, including ‘beehive’, ‘button’, and ‘cactus’, and there are double, semi-double and dahlia-like ‘pompon’ flowered varieties. The plants also come in different heights that range from dwarfs not exceeding 15cm in height to cut flower beauties that grow 90cm tall.

Zinnia 'Zahara' mix. Picture courtesy BallStraathofZinnia 'Zahara' mix. Picture courtesy BallStraathofIn the Garden:

From petunia pink to daisy yellow, zinnias come in every eye-catching hue (except true blue), and because both single and mixed colours are available, you can match them with your favourite perennial or annual flowers, as well as foliage plants. They are also invaluable in herb and vegetable gardens, attracting many pollinators. They look especially beautiful when you sprinkle your seeds among a mixture of flowers such as dahlias, marigolds, asters, and petunias.

In the symbolism of flowers it is said that zinnias symbolize thoughts of absent friends, and for those who are present, they are sure to spark loads of admiration from family, friends, and casual passers-by alike. Other creatures love them too, and wherever they are planted butterflies bees and other pollinators will be attracted to their cheery flowers.

Zinnias are popular for cutting gardens and will brighten up any bouquet. The dwarf varieties are beautiful in mixed containers, window boxes and hanging baskets, and are also reliable border plants, while the taller varieties are perfect for the background of a garden bed. There’s really a zinnia for every garden!

Cultivation/Propagation:

Zinnias grow best in climates with long, hot, dry summers, and grow well throughout South Africa because they are extremely heat tolerant and water-wise. However, in humid regions they are susceptible to fungal diseases, but new and improved varieties like 'Zahara' and ‘Profusion’ are available that are more resistant to rust and other fungal diseases.

Zinnia Double 'Zahara' Raspberry Ripple. Picture courtesy BallStraathofZinnia Double 'Zahara' Raspberry Ripple. Picture courtesy BallStraathofGrowing zinnias from seed might be one of the easiest gardening tasks of the year. As soon as the weather warms up in spring they are sown directly into garden beds, where they will germinate within four to seven days in soil temperatures between 20 and 24°C, and the plants should start flowering within 8 to 10 weeks after sowing.

If you prefer to buy zinnia plants in seedling trays from your garden centre, to ease their transition in the garden, prune the plants back by one-third, then sit back and watch your zinnia patch mature and flourish. If you sow or plant zinnias every couple of weeks at the beginning of summer, this will extend their flowering period.

Choosing a location that gets full sun is essential for them to bloom at their fullest potential. Zinnias are adaptable to most soil conditions, but the ideal soil will be well-drained and fairly rich in organic matter. Soil with a pH between 5.5 and 7.5 is ideal.

Sow as per the instructions on your seed packet and cover with soil as they require darkness to germinate. Keep the beds moist but not soggy until germination takes place.  Once established zinnias are quite drought tolerant and should be watered judiciously. To maximize growth and blooms fertilise lightly with any good product for flowering plants, and to encourage the plants to produce more blooms, cut off the old flowers regularly - a process called “deadheading”.

Zinnias are summer annuals and will die with the first hard frost.  If you want them to reseed, let the last flowers of the season mature fully and scatter their seeds.

Zinnia 'Zahara' Double Fire. Picture courtesy BallStraathofZinnia 'Zahara' Double Fire. Picture courtesy BallStraathof

Problems, Pests & Diseases:

Bacterial and fungal spots, powdery mildew, and bacterial wilt may affect zinnias. Minimize wetting of foliage and space the plants properly to allow good air circulation around the leaves.

Caterpillars, mealybugs, and spider mites may also cause problems. Some leaf damage is not an issue, so avoid spraying unless there’s a true infestation.

Toxicity:

Zinnias are not a poisonous plant and are safe for gardens frequented by children. They are also safe to plant around animals because they are non-toxic to dogs, cats and horses. However, they are not a culinary flower, and are not used as food garnishes, etc.  

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