Elephant Garlic (Allium ampeloprasum var. ampeloprasum)
13 sources cited · Verified
The short answer
- Ready in
- 365–730 days
- Site
- soil pH 6–6.5
- Biggest risk
- Allium white rot
In the UK, elephant garlic are ready to harvest 365–730 days after planting.
Elephant garlic (Allium ampeloprasum var. ampeloprasum) — Herbaceous perennial grown as a biennial-style crop.
Core growing advice on this page is checked against named horticultural and university-extension sources — see References.
At a Glance
Quick Facts
| Factor | Value |
|---|---|
| Soil pH | 6 - 6.5 |
| Optimal growing temp | 18-24C |
| Minimum survivable temp | -5C |
| Time to harvest | 365-730 days |
| Drainage | Chalk, Clay, Loam, Sand; moist but well-drained or well-drained; avoid heavy clay prone to winter saturation (grow in containers if so) |
| Lifecycle | Herbaceous perennial grown as a biennial-style crop: cloves are planted in autumn, overwinter (they need a cold period), and are harvested the following summer. Fully frost-hardy (H6); very often left to flower and to form offsets if not lifted. |
| Edible parts | bulb (cloves) |
When to plant in the USA
United States. Elephant garlic is planted in autumn, so it is timed against the approach of winter rather than against the last spring frost — Utah State gives late September to November for its own conditions. The event to plant ahead of is the ground freezing hard, which comes later than the first air frost and is not what a frost normal measures, so use your own local experience of when the soil sets rather than a date taken from elsewhere. Set cloves 2-3 in deep, 3-4 in apart, in rows 6-10 in apart, and mulch after planting where winters are severe. Each clove makes one bulb. Worth knowing before you plan the bed: elephant garlic is not garlic. Utah State notes it is very mild, stores poorly, and is more closely related to leek — it is Allium ampeloprasum, the same species as leek, so it belongs in a leek rotation rather than a garlic one.
Soil & Growing Conditions
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Planting & Establishment | 0 | Elephant garlic is grown from individual cloves, planted in autumn - RHS advises it is "best planted in October" - so it gets the winter cold it needs and a long growing season. PLANTING DEPTH & SPACING: split the bulb into cloves and plant each one upright (pointed end up) so the tip sits about 2.5cm (1in) below the soil surface; the RHS garlic spacing is 15cm (6in) between cloves in rows 30cm (12in) apart, but because elephant garlic grows so large (up to 1-1.5m tall) many gardeners give it more room, around 20-30cm apart. In light soil, deeper planting can give bigger bulbs, but do not plant deep in heavy soil. Choose a sunny, open site on fertile, free-draining ground; on cold, wet clay grow it in large containers instead. Roots establish before winter. |
| Leaf Growth | 3 | Through winter and spring the clove grows into a tall, leek-like plant with broad blue-green leaves. Keep the bed weed-free so the plants are not crowded, and water in prolonged dry spells in spring. Feed only if the soil is poor. In early summer the plant throws up a tall flower stalk (scape) - cut this out as soon as it appears (and eat it, sauteed or roasted) so the plant puts its energy into the bulb rather than flowering. |
| Bulb Development | 7 | Through early to mid-summer the base swells into a large bulb that divides into a few very large cloves, sometimes with small hard "cormel" offsets around the outside. Ease off watering as the leaves begin to yellow so the skins firm and the bulb stores well. Keep weeding lightly; no further feeding is needed. |
| Harvest & Curing | 8 | Lift the bulbs once the leaves have turned yellow - for autumn-planted elephant garlic this is usually in mid- to late summer, after a long season (roughly 9-10 months from planting). Ease each bulb up gently with a fork rather than pulling, on a dry day. Dry (cure) the bulbs for two to four weeks in a warm, airy place until the skins are papery, then store them somewhere cool and dry at about 5-10C, where they keep for several months. Save the largest cloves and any cormel offsets to replant the following autumn. |
Harvest & Storage
Diseases
Pests
Elephant Garlic, Clove to Harvest
References
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Qualitative only: southern/coastal last air frost often before end of April; further north well into May, in a few places into June. No numeric per-region frost dates published here.
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Tier 1. US extension source: plant garlic from late September to November, cloves 2-3 in deep in rows 6-10 in apart with cloves 3-4 in apart in the row; each planted clove produces one bulb of 10-15 cloves; harvest when tops begin to yellow or fall over but before completely dry; cure the whole plant in a shady warm spot 1-2 weeks until skins are papery and roots dry; store at 32-40F, dry, avoiding freezing. States that elephant garlic is very mild, stores poorly and is more closely related to leek than to garlic.
13 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
How long do elephant garlic take to grow?
Typically 365–730 days, depending on cultivar and growing conditions.
What soil pH do elephant garlic need?
A pH of about 6–6.5. 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 elephant garlic?
Our data links 2 diseases and 4 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
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.