Blue is a hard colour to find in the flower world, and delphiniums and larkspurs have it in spades.

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Delphinium cultorum 'Magic Fountains Sky Blue White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Sky Blue White Bee' Picture courtesy Ball StraathofIt is not difficult to imagine why Delphiniums are known as the “queen of the border” with their tall spikes of densely packed flowers in exquisite shades of soft lavender, light to deep blue, violet-purple, white and rose. Larkspurs are also unforgettable and easy to grow from seed. Read all about growing these beauties below.

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.

Delphinium 'Guardian Blue'  Picture courtesy www.ballstraathof.co.zaDelphinium 'Guardian Blue' Picture courtesy www.ballstraathof.co.zaIn 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.

There 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 'Diamonds Blue' Picture courtesy www.ballstraathof.co.zaDelphinium 'Diamonds Blue' Picture courtesy www.ballstraathof.co.zaDelphinium

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.

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. 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.

Delphinium cultorum 'Guardian' White. Picture courtesy Ball StraathofDelphinium cultorum 'Guardian' White. Picture courtesy Ball StraathofLike 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 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’

Delphinium cultorum 'Magic Fountains Lilac Pink White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Lilac Pink White Bee' Picture courtesy Ball StraathofThe 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.

Look 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.Delphinium cultorum 'Magic Fountains Lavender White Bee' Picture courtesy Ball StraathofDelphinium cultorum 'Magic Fountains Lavender White Bee' Picture courtesy Ball Straathof

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 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’

Delphinium 'Guardian Lavender' Picture courtesy www.ballstraathof.co.zaDelphinium 'Guardian Lavender' Picture courtesy www.ballstraathof.co.zaDiamonds 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 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' Picture courtesy Ball StraathofDelphinium x belladonna 'Blue Donna' Picture courtesy Ball StraathofDelphinium 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 ‘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.

Delphinium 'Magic Fountains Mixed' Picture courtesy www.nuleaf.co.zaDelphinium 'Magic Fountains Mixed' Picture courtesy www.nuleaf.co.zaDelphiniums 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.

Delphinium 'Casablanca' Picture courtesy www.ballstraathof.co.zaDelphinium 'Casablanca' Picture courtesy www.ballstraathof.co.zaDelphiniums 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.

Larkspur (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

Delphinium consolida 'Summer Colors' Picture courtesy Ball StraathofDelphinium consolida 'Summer Colors' Picture courtesy Ball Straathof

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.

Larkspurs 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.

Delphinium consolida 'Summer Nights' Picture courtesy Ball StraathofDelphinium consolida 'Summer Nights' Picture courtesy Ball StraathofAlthough 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 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.

Delphinium consolida 'Summer Stars' Picture courtesy Ball StraathofDelphinium consolida 'Summer Stars' Picture courtesy Ball Straathof‘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.