About

A clump-forming perennial, to around 1.5m high in flower, with palmately lobed and toothed green leaves. Tall spikes of violet flowers with white 'eyes' are produced in summer.

About the genus

Delphinium can be annuals, biennials or perennials, with palmately lobed basal leaves and showy bowl-shaped flowers in spikes, racemes or panicles

Growing conditions

SunlightFull sun
Soil typeChalk, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectSouth-facing, West-facing, East-facing
ExposureSheltered
UK hardinessH5

Plant details

Plant typeHerbaceous Perennial
HabitColumnar upright
FoliageDeciduous
Height1-1.5 metres
Spread0.5-1 metres
Time to full height1-2 years
Suggested usesCottage and informal garden
ToxicityHumans/Pets: Harmful if eaten. Wear gloves and other protective equipment when handling. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants

Care notes

CultivationGrow in fertile, well-drained soil in full sun. Shelter from strong winds and provide support (see staking perennials). Divide every 2-5 years to maintain vigour. See staking perennials and delphinium cultivation for further advice
PruningDeadhead main stem after flowering to encourage side shoots to flower. Cut back to ground level in autumn
PropagationPropagate by division or by basal softwood cuttings in spring
Pest resistanceMay be susceptible to aphids, slugs, snails, leaf miners and caterpillars, including swift moth caterpillar
Disease resistanceMay be susceptible to delphinium black blotch, Powdery mildews, grey moulds, crown rot (on mature plants) and occasionally cucumber mosaic virus