Allium nigrum
black garlic
Bulbous perennial about 40cm or more tall, with lance-shaped, grey-green basal leaves to 50cm long. Open, cup-shaped creamy-white flowers, occasionally lilac, with a central greenish-black ovary, form rounded clusters with a flattened top, up to 7cm across, in early summer
Other common names
broad-leaved onionSynonyms
Allium speciosumAllium multibulbosum
see moreAllium nigrum var. multibulbosum
Allium bauerianum
Allium monspessulanum
Size
Ultimate height
0.5–1 metresTime to ultimate height
1–2 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drained, Well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Grey Silver Green | |||
|---|---|---|---|---|
| Summer | Cream White | Grey Silver Green | ||
| Autumn | ||||
| Winter |
Position
- Full sun
Aspect
West–facing or South–facing
Exposure
Sheltered Hardiness
H5Botanical 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
Correct
- Plant range
- Mediterranean
How to grow
Cultivation
Easy to grow in fertile well-drained soil. Add grit when grown in clay soils to improve drainage. See allium cultivation
Propagation
Propagate by seed, sowing in containers in a cold frame when just ripe or in the spring. Alternatively, remove offsets in autumn
Suggested planting locations and garden types
- City and courtyard gardens
- Gravel garden
- Cottage and informal garden
- Patio and container plants
- Wildlife gardens
- Flower borders and beds
- Cut flowers
Pruning
No pruning required, other than to remove old flowered stems and foliage
Pests
May be susceptible to allium leaf miner and onion fly
Diseases
May be susceptible to onion white rot, and onion downy mildew
Get involved
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