GardenWizzPlant Care Card

Allium

Allium hollandicum · Bulb

Hardiness
H7 Very hardy (to below −20°C)
Position
Full sun
Height × Spread
90 cm × —
Soil
Moist but well-drained, fertile soil; avoid damp sites on heavy soil.
Flowering
May–June
Toxicity
No toxicity recorded

The Gardening Year

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Sow
🪴 Plant out
🌸 In flower

Watch out for

Allium leaf miner: Remove affected foliage immediately after flowering and burn it to break the pest's life cycle.

Onion fly: Plant in autumn or early spring outside peak flight times and use insect-proof netting as a barrier.

Onion white rot: Avoid planting alliums in infected soil for at least 10 years and ensure excellent drainage.

Onion downy mildew: Improve air circulation, avoid overhead watering, and remove severely infected leaves promptly.

Bulb rot: Plant in well-drained soil or containers and avoid sites that remain wet during winter.

Full guide: gardenwizz.com/plants/allium-hollandicum © GardenWizz — UK gardening encyclopedia