Keel-leaved Garlic (Allium carinatum)
2 sources cited · Verified
The short answer
- Site
- 6+ hours of sun, soil pH 6.5–8
- Biggest risk
- Allium white rot
Keel-leaved garlics (Allium carinatum) — bulbous herbaceous perennial.
Unlike an annual crop, the work here is front-loaded into establishment: get the planting and the site right and the same plants crop for several seasons.
Core growing advice on this page is checked against named horticultural and university-extension sources — see References.
Soil & Growing Conditions
Water: moist but well-drained or well-drained (RHS); drought-tolerant once established (Practical Plants)
Soil pH range
Span reflects genuine variation between the cited authorities, not a single agreed figure.
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Propagation | 0 | Propagate by offsets detached after lifting the bulb once flowering has finished, or sow seed in a cold frame in spring; bulb division best done in autumn (RHS, Practical Plants). |
| Establishment and spread | 3 | Rapidly spreading bulbous perennial with linear mid-green leaves to 8cm; full sun, well-drained soil; best suited to informal plantings given its vigour (RHS). |
| Flowering | 6 | Midsummer: loose umbels of up to 30 bell-shaped purple flowers to 5cm across, often mixed with bulbils (RHS). |
| Maintenance / dieback | 9 | Remove old flowered stems and foliage; no other pruning needed (RHS). Time to maturity 2-5 years. |
Quick Facts
| Factor | Value |
|---|---|
| Soil pH | 6.5 - 8 |
| Sunlight | 6-6 hours direct sun |
| Soil texture | chalk, loam or sand (RHS); loamy preferred (Practical Plants) |
| Drainage | well-drained |
| Lifecycle | bulbous herbaceous perennial |
| Edible parts | leaves, bulbs, bulbils |
At a Glance
Harvest & Storage
When to pick: Bulbs, leaves and bulbils are all usable; bulbils forming alongside the midsummer flowers can be harvested for propagation or use much like garlic bulbils, and the plant's rapid spread by offsets means established clumps can be divided and lifted after flowering finishes (RHS).
Diseases
Pests
Keel-leaved Garlic, Bud to Bloom
References
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Keeled garlic (also witch's garlic) is a perennial herb native to grasslands, rocky outcrops and open woodlands in central and southern Europe and Asiatic Turkey. Prefers full sun to part shade, well-drained loamy soil, slightly acidic to neutral pH; drought-tolerant once established, minimal maintenance. Seed propagation: sow spring in a cold frame, prick out seedlings into individual pots once large enough to handle. Bulb division best done in autumn.
-
Hardiness H5 (hardy in most UK locations, even severe winters). Full sun; south, west or east-facing aspect. Soil: chalk, loam or sand; moist but well-drained or well-drained; pH alkaline or neutral. Height 0.5-1m, spread 0.1-0.5m. Time to maturity 2-5 years. Bulbous perennial, linear mid-green leaves to 8cm, loose umbels of up to 30 bell-shaped purple flowers to 5cm across, often with bulbils, borne during midsummer. Propagate by offsets, carefully detached by lifting the bulb after flowering has finished; spreads rapidly, best suited to informal plantings. Maintenance: no pruning needed except removal of old flowered stems and foliage. PESTS: Allium leaf miner, onion fly. DISEASES: onion white rot, onion downy mildew -- named directly for this species, not inferred. Toxic to pets.
2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.
Frequently Asked Questions
What soil pH do keel-leaved garlics need?
A pH of about 6.5–8. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.
What problems affect keel-leaved garlics?
Our data links 2 diseases and 2 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
Almost everything on this page resolves to your own frost dates rather than the calendar — the last spring frost moves by roughly two months between zone 3 and zone 10. The USA Garden Planner works from your zone so the timing is already decided before the season starts.
Get the USA Garden Planner →Instant PDF download · Written for US growing conditions
Last verified 2026-08-28
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Plan the next step
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