— Varies by species (Species-specific rating required: Check the exact species and cultivar before overwintering)
Position
Full sun
Height × Spread
10–250 cm
Soil
Moist but well-drained soil; rich in nutrients or improved with well-rotted compost/manure. Avoid poorly drained, permanently wet, or very heavy clay soils without improvement.
Flowering
June–July
Toxicity
Toxic to humans and livestock
The Gardening Year
J
F
M
A
M
J
J
A
S
O
N
D
🌱 Sow
🪴 Plant out
🌸 In flower
Watch out for
Black blotch: Remove affected plant parts immediately and avoid saving seed from infected plants.
Powdery mildew: Ensure good air circulation and apply a suitable fungicide if infection is severe.
Slugs and snails: Protect new shoots with physical barriers or use slug pellets around the base of plants.
Delphinium moth caterpillars: Inspect plants regularly and hand-pick caterpillars as soon as they are spotted.