About
A tall herbaceous perennial to 2.2m, with divided foliage and light, lilac-mauve flowers, with pale brown eyes, in racemes to 75cm in length.
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
AspectWest-facing, South-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, City and courtyard gardens
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. Apply a balanced liquid every couple of weeks in the growing season. For the 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. Cut down all growth to ground level after it has withered in autumn
PropagationPropagate by taking pencil thick basal 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