About
A tall, clump-forming perennial to 1.8m high in flower, with mounds of lobed and toothed leaves at the base. Tall spikes packed with clear blue flowers with dark '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
ExposureSheltered
UK hardinessH5
Plant details
Plant typeHerbaceous Perennial
HabitClump forming
FoliageDeciduous
Height1.5-2.5 metres
Spread0.5-1 metres
Time to full height2-5 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