Size
Ultimate height
0.1–0.5 metresTime to ultimate height
1 yearUltimate spread
0–0.1 metreGrowing conditions
Moisture
Moist but well–drainedpH
Neutral, AlkalineColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Green | |||
| Autumn | ||||
| Winter |
Position
- Full sun
Aspect
East–facing or South–facing or West–facing
Exposure
Sheltered Hardiness
H4Botanical details
- Family
- Amaryllidaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Genus
Allium are bulbous herbaceous perennials with a strong onion or garlic scent, linear, strap-shaped or cylindrical basal leaves and star-shaped or bell-shaped flowers in an umbel on a leafless stem
- Name status
Accepted
How to grow
Cultivation
Thin plants to 15cm apart. Water in dry weather and feed every two weeks with a general purpose fertiliser. Cease watering and feeding once bulbs have swollen in mid-summer. Onions can be harvested as soon as they're big enough to use. See advice profiles for onions and shallots for further information
Propagation
Propagate by seed or by onion sets. See how to grow: onions or sowing vegetable seeds
Suggested planting locations and garden types
Pruning
No pruning required
Pests
May be susceptible to onion fly and allium leaf miner
Diseases
May be susceptible to onion white rot, leek rust and onion downy mildew
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.