Delphinium

Botanical/Latin
   Delphinium

Pronunciation
   dell-fin-ee-um

Common Name
   Larkspur

Hardiness zone range
   3 - 7

General Comments
Think of Delphiniums and images of long summer borders of tall spires of blue come racing into mind. They have an elegance and majestic beauty that is truly awesome. Our second thought is of the culture and care that we, as busy everyday gardeners, may find challenging to provide. Recognizing that these situations exist, we have selected a range of modern day varieties that combines their splendor and elegance with shorter stature and a more forgiving cultural disposition.

Uses
They are wonderful in old fashioned style, period, or cottage gardens, where their stately elegance fits right in. In perennial beds and borders, or even in mixed plantings with shrubs and roses, they look equally superb.

They are outstanding cut flowers, and make great subjects for inclusion in a cutting garden where the cultural needs may be easier to meet and supply.

Light Preference
Sun, with a tolerance for a little light shade.

Sunny conditions are required, but in some situations heat stress will take its toll. Try to find a position that offers some protection from the heat of the mid-day sun.

Culture
They need sheltered positions in rich, fertile soils that drain well but have the capacity to retain moisture in dry weather; the addition of organic matter (composted manure, garden compost, leaf mold, peat, etc.) at planting time is important. Quickly drying sandy soils and poorly draining clay soils should be avoided. They prefer soils that are on the alkaline side of neutral, so check the pH level and adjust accordingly.

These shorter plants require less support, but, as an "insurance policy", it is worth putting some branches of birch or other finely branched tree over the emerging shoots in spring, or staking the developing flower shoots to protect against winds and storms.

After flowering, the old flowering stems should be cut back; this stimulates new basal growth and maintains vigor in the clumps and may lead to another flush of flowers.

Background
They were cultivated by ancient apothecaries as medicinal plants. It is from around this time that the Greek word Delphis was used to describe the genus; it comes from the shape of unopened flower buds, which resemble a dolphin's nose. The common name also has origins based on the flower's shape; they have a spur that resembled those of a lark, hence Larkspur or Lark's Heel.

Some species were used as insecticides against lice, apparently used on soldiers as recently as the battle of Waterloo and the American Civil War.

Delphiniums are found in nature to be one of the very few plant types to have the three primary colors in its genus, and it is from these naturally occurring species that plant breeders are continually developing new strains and cultivars. The tall, large flowered hybrids were developed first at the famous English nurseries of Kelway of Langport, and later by several other firms including Blackmore & Langdon and Lemoine in France. Growing as tall as eight feet, in single and double forms, and in a wide color range, they make spectacular displays, especially when massed together. Requiring a high degree of care and attention, breeders in Holland, Germany, USA, and more recently New Zealand have endeavored to develop Delphiniums with easier culture, shorter stature, increased color range, and greater disease resistance.

These modern hybrids are the result of all this work and dedication. They still require good culture and careful attention, but the rewards outweigh the effort and make it all worthwhile. They are sometimes called the "queen of the perennial border" where they sit proudly on the throne in many fine gardens around the world.

Splendor Suggestions
Delphiniums force well and respond well to good pot culture. Consider raising a few in containers and forcing in a well-lit greenhouse to make spectacular conversation pieces and to enjoy in advance of the other outdoor varieties.

Companion Plants
In old fashioned borders, they associate well with Lilium (Lilies), especially the large flowered and heavily scented Oriental types. The tall stems of Alcea (Hollyhocks) enjoy the same sheltered positions and stand out well against solid backgrounds like walls, fences, or tall evergreens.

Lower growing partners like Gypsophilas, Artemisia 'Powis Castle', Phlox, and Nepetas are good to position in front of them.