Delphinium delavayi Seeds | Delavay’s Larkspur

Delavay's Larkspur (Delphinium delavayi) with tall branching spires of deep-blue flowers in a mountain meadow setting — Delavay’s Larkspur (*Delphinium delavayi*): Ranunculaceae, a tall alpine larkspur of Yunnan with deep-blue summer spires.

LATIN NAME: Delphinium delavayi

COMMON NAME: Delavay’s Larkspur

Plant Profile

Delavay’s Larkspur is a tall perennial of the Yunnan mountains, growing a metre and more, with finely cut, lobed leaves and strong, branching spires of deep-blue flowers through midsummer. Each flower carries the genus’s signature spur behind the petals, and the blooms open in long, dense racemes that stand well above the border and hold their colour for weeks.

It flourishes in deep, rich, moist soil and stands firm in a sheltered spot, and after the first heads are cut it often throws a second, lighter flush in late summer. The plant carries the stately, upright look of the high-mountain delphiniums. The stems are reddish-tinged and hold themselves upright without staking in sheltered sites, though a single wind event in flower is enough to justify a support thereafter.

Science & Biotechnology

The species belongs to the high-mountain group of delphiniums that shaped the modern garden hybrids, and it features in studies of the genus’s alpine flora and in the breeding records behind the border delphiniums of European gardens.

Like the whole genus it is toxic, carrying alkaloids concentrated in the foliage and seeds; the chemistry has been documented in toxicological work, and the practical rule is simple: admire the spires, keep them from children and grazing animals. Delphinium alkaloids are among the most studied of the ranunculacean toxins, and the genus’s chemistry has been mapped in veterinary toxicology as well as in pharmacognosy. Botanists treat the Yunnan larkspurs as a variable group, and this species has been separated from its close relatives by spur shape and hair characters in recent treatments.

Uses & Benefits

In the border it provides the vertical accent that gardeners have sought from delphiniums for two centuries: deep-blue spires through midsummer, bee-centred flowers drawing bees and butterflies, and cut stems that last well in the vase.

Cut the first flush hard and the plant often rewards a second; in the garden its demands are few beyond rich soil, moisture and shelter from wind. In the cut-flower trade the species’ spires are valued for their length and the depth of the blue, and stems conditioned overnight in deep water last a week or more in the vase. In cottage-garden schemes it fills the same role the border delphiniums do, holding the middle and back of the bed with vertical blue through the height of summer.

Growing from Seed

Level a tray of loose seed compost, sow evenly, cover to about the seed’s own depth, and keep it moist in full light; a chill of two to four weeks in the refrigerator improves and evens germination.

Grow the seedlings cool and bright, pot them on once, and plant out into deep, enriched soil in a sheltered, sunny position. Stake the spires before the flower stems lean, and cut the first flush at the base to invite the second. Water at the base rather than overhead, since wet foliage in a sheltered border invites the mildew that is the delphinium’s one persistent enemy. Renew the clumps from seed every few years, since delphinium crowns tire with age, and a fresh generation of seedlings costs little space in a cold frame.

Our Take

A mountain larkspur of the old style: tall, deep-blue, and generous with a second flush if you cut the first. Rich soil, cool roots, and a stake in time.

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