About
Delphinium elatum, the alpine delphinium, is a tall, erect, clump-forming perennial to around 1.8 m with deeply divided leaves and stiff, erect spires of dark purplish-blue, spurred flowers in summer. The original parent of many of the modern large-flowered hybrid delphiniums.
About the genus
Delphinium, the larkspurs and delphiniums, are annuals, biennials and perennials with palmately lobed basal leaves and tall spikes, racemes or panicles of showy, spurred flowers in shades of blue, purple, pink, white or yellow in early summer. Among the most dramatic of all border perennials.
Growing conditions
SunlightFull sun
Soil typeChalk, Clay, 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
Height1.5-2.5 metres
Spread0.5-1 metres
Time to full height2-5 years
Suggested usesCottage and informal garden, Wildlife gardens
Native toEurope to N & C Asia
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 a fertile, well-drained soil in full sun; shelter from strong winds and stake well. For best flower spikes thin shoots when 7cm high to leave a minimum of 2-3 shoots on young plants and 5-7 shoots on established plants. See staking perennials and delphinium cultivation for further advice
PruningDeadhead by cutting spent flower spikes back to small flowering side shoots. Removing of the flower spikes straight after flowering may encourage a second flush of flowers in late summer. Cut down all growth to ground level after it has withered in autumn
PropagationPropagate by taking pencil-thick, basal, softwood cuttings in early spring
Pest resistanceMay be susceptible to aphids, earwigs, delphinium leaf miner, delphinium moth caterpillars, slugs, snails and caterpillars
Disease resistanceMay be susceptible to powdery mildews, delphinium black blotch, crown rot and viruses