Allium triquetrum
three-cornered garlic
A bulbous plant with a triangular stalk up to 40cm tall and star-shaped flowers, petals each with a single green vein, produced from April to June. This attractive but rather weedy onion, native to southern Europe is occasionally cultivated intentionally but invariably becomes a nuisance, as it spreads freely by both bulbils and seeds
Size
Ultimate height
0.1–0.5 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green White | Green | ||
|---|---|---|---|---|
| Summer | Green White | Green | ||
| Autumn | Green | |||
| Winter |
Position
- Full sun
- Partial shade
Aspect
East–facing or South–facing or West–facing
Exposure
Sheltered Hardiness
H5Botanical details
- Family
- Amaryllidaceae
- Native to the UK
- 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
Correct
How to grow
Cultivation
This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild IN ENGLAND WALES, NORTHERN IRELAND and the REPUBLIC OF IRELAND. Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information
Propagation
Please see cultivation notes
Suggested planting locations and garden types
- Cottage and informal garden
- Wildflower meadow
- Wildlife gardens
- Ground cover
Pruning
No pruning required
Pests
Generally pest-free
Diseases
Generally disease-free
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.