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Delphinium

By Rupert Foxton-Smythe

delphinium, flower, larkspur-4892835.jpg

Delphiniums, with their tall stature and vibrant flowers, have captivated gardeners for centuries. Discover how to grow them to perfection in your own garden.

TL;DR

Delphiniums are tall and eye-catching border plants with large flowers in various colors. They require fertile, well-drained soil and careful maintenance to grow to perfection. The main flowering period is in June and July, but cutting back the stems can induce another flush of flowers in autumn. The plants should be lifted and divided every few years to maintain vigor.

  • Tall and eye-catching border plants with large flowers
  • Require fertile, well-drained soil and careful maintenance
  • Main flowering period in June and July, with the possibility of another flush in autumn

Many people have resolved to grow Delphiniums after seeing a group of well-grown giants towering over their heads in a border owned by an experienced gardener. Spikes clothed with large flowers in white, blue, pink, mauve or purple – hardly any other border plant can catch the eye in quite the same way. You can, of course, achieve the same sort of results if you have the space, but tall Delphiniums are not easy plants to grow to perfection. You will need to ensure that the soil is fertile and well drained and planting should take place in spring. Strong canes will have to be inserted at an early stage and you must keep careful watch for slugs and powdery mildew. Water in dry weather. When the main

Flowering period: during June and July has passed, cut back the flowering stems to induce another flush of flowers in autumn. In late autumn cut the stems down to ground level. The plants will slowly deteriorate with age and there is nothing you can do about it. The answer is to lift the clumps in spring every few years and divide them, replanting only the most vigorous sections.

VARIETIES: The popular garden varieties have been derived from D. elatum and are placed in 3 groups. The Elatum group have the classical Delphinium shape and flower form, growing up to 8 ft tall with upright spikes bearing large flat flowers which may be semi-double or double. The tall ones (height 5-8 ft. Spacing 2.5 ft) include ‘Vespers’ (blue-mauve), ‘Butterball’ (cream) and ‘Mullion’ (blue). Amongst the dwarfs (height 3-4 1/2 ft. Spacing 1.5 ft) can be found ‘Mighty Atom’ (lilac), ‘Cinderella’ (purple) and ‘BlueTit’ (dark blue). The second major section of Delphiniums is the Belladonna group – height 3-4 ft. Spacing 1.5 ft. These slender plants produce branching flower-heads which bear cupped (not flat) blooms. Compared with the Elatum group, the flowers are smaller and more widespread – the popular varieties are ‘Pink Sensation’ (pink) and ‘Blue Bees’ (pale blue). The third section is the Pacific Giants group – tall and large flowered, they can be raised from seed but unfortunately live only for a few years. Buy a mixture or a named variety, such as ‘Galahad’ (white) or ‘King Arthur’ (purple).

SITE AND SOIL: Well-drained and fertile soil is necessary-thrives best in a sunny and sheltered situation.

D. elatum

Belladonna group

D. elatum

Pacific Giants group

PROPAGATION: Plant cuttings in April or divide clumps in spring. Sow Pacific Giants seeds under glass in early spring.

Many people have resolved to grow Delphiniums after seeing a group of well-grown giants towering over their heads in a border owned by an experienced gardener.

More Information on DELPHINIUM

Delphiniums, with their tall stature and vibrant flowers, have captivated gardeners for centuries. These magnificent border plants can create a stunning visual impact, especially when they reach towering heights under the care of experienced gardeners. Their spikes adorned with large flowers in various shades of white, blue, pink, mauve, and purple make them stand out in any garden. To grow Delphiniums to perfection, several factors need careful consideration. These plants thrive in fertile, well-drained soil, so it's essential to ensure the right soil conditions. Planting should ideally take place in spring, and strong canes should be inserted early on to provide support as the plants grow. Vigilance against slugs and powdery mildew is crucial, and watering is necessary during dry spells. The main flowering period of Delphiniums occurs during June and July, but gardeners can encourage another flush of flowers in autumn by cutting back the flowering stems. However, it's important to note that Delphiniums slowly deteriorate with age. To maintain their vitality, lifting and dividing the clumps every few years is recommended, replanting only the most vigorous sections. Delphiniums belong to the family Ranunculaceae and are native to the Northern Hemisphere. They have been cultivated in gardens for their beauty and elegance for centuries. In addition to their stunning appearance, Delphiniums also attract pollinators like bees and butterflies, making them beneficial for the overall ecosystem. With their classical Delphinium shape and flower form, the Elatum group is particularly striking, reaching heights of up to 8 feet. Varieties like 'Vespers' (blue-mauve), 'Butterball' (cream), and 'Mullion' (blue) are popular choices among gardeners. The Belladonna group, on the other hand, produces slender plants with branching flower-heads and cupped blooms. Varieties such as 'Pink Sensation' (pink) and 'Blue Bees' (pale blue) are well-loved in this category. In conclusion, growing Delphiniums can be a rewarding but challenging endeavor. Their majestic presence and vibrant colors make them a standout choice for any garden, but attention to soil conditions, maintenance, and proper care are essential for achieving optimal growth and longevity.

About the author

Rupert Foxton-Smythe

Rupert Foxton-Smythe is a seasoned horticulturist and avid plant enthusiast with over three decades of experience in the field of botany. As a leading expert at Houseplant Guru, Rupert brings a wealth of knowledge and a deep passion for all things green.

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