Alpine Delphinium

How to grow Alpine Delphinium

Written by the GardenDecoded editorial team · Last reviewed 21 July 2026 · Written for UK gardens · How we research our guidance

Planting

Plant in spring into ground improved with plenty of well-rotted manure or compost, in a sunny spot sheltered from wind. Delphiniums are hungry and thirsty, and thin poor soil produces thin poor spikes. Put the stakes in at planting time.

Pruning

Thin the shoots in spring to the five or six strongest on an established clump; this gives better spikes than leaving everything. Cut the flowered spike down to a low leaf once it fades and a smaller second flush often follows in early autumn. Cut everything to the ground in late autumn.

Propagation

Take basal cuttings in early spring when shoots are about 8 cm tall, cutting them with a sliver of the crown. Division in spring also works. Seed of named cultivars will not come true.

Pests and diseases

Slugs and snails are the single biggest threat and can destroy the emerging spring shoots overnight. Powdery mildew is common in dry summers, and delphiniums are also susceptible to a bacterial black blotch on the leaves.

Value to wildlife

Bumblebees work the spikes heavily through June and July.

Notes

Support and slug control decide whether you get a delphinium or a disappointment. Stake before the stems reach 30 cm, because a spike broken in a summer storm cannot be salvaged.

This guidance was researched and written by GardenDecoded — see our editorial policy for how guides are checked and reviewed.

Other names for this plant

These names have all been used for Delphinium elatum but are no longer the accepted name. You may still meet them on old labels, in books, or in nursery catalogues.

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