Overview
What garlic needs, when it crops, and whether it suits your garden.
Each clove you plant in autumn becomes a whole bulb by the next summer, and all it asks for is a spell of winter cold, sun and soil that doesn’t sit wet. What matters most is good planting stock, not supermarket bulbs, and timing at both ends: plant before the ground freezes, and lift as the leaves yellow, before the bulbs split.
Quick facts
- Botanical name
- Allium sativum
- Soil pH
- 6.0
- Feeding
- Moderate feeder
- Hardiness
- Any zone, as an annual
- Time to harvest
- 250 – 270 days
- Propagation
- Bulb
Growing details
- Spacing
- 15 cm (6 in)
- Sowing depth
- 50 mm (2 in)
- Frost sensitivity
- Frost hardy
Growing calendar
- Plant out: February, March, October, November, December
- Harvest: May, June, July, August
Cloves mid-autumn to early winter; some varieties in late winter or early spring. Autumn plantings late spring to summer; spring plantings mid to late summer.
Is this plant right for you?
- Plant in autumn
- Needs winter cold
- Low maintenance
- Stores for months
- Good in deep pots
- Needs drainage
- Toxic to pets
Toxic to pets
Toxic to dogs, cats and horses (ASPCA).
Before You Grow
Choose hardneck or softneck for your climate, and a sunny spot that drains well in winter.
Buy named, disease-free planting garlic: supermarket bulbs may be unsuited to your climate or carry disease.
What you need
Planting garlic
Named, certified disease-free bulbs from a garden centre or supplier. See choose your garlic.
A sunny, free-draining spot
Garlic rots in soil that sits wet over winter. See where it grows best.
Compost or manure
Two bucketfuls per square metre, well rotted. See soil.
A dibber or trowel
For planting cloves at the right depth. See how to plant.
Fleece or netting
Birds pull up newly planted cloves. See common problems.
Straw mulch in cold areas
To protect autumn plantings over winter. See watering and mulching.
Choose your garlic
Garlic comes in two main types, with many named varieties of each. Buy bulbs sold for planting: supermarket garlic may be unsuited to your climate, may carry disease, and is often treated to stop it sprouting (RHS, Iowa State).
Hardneck garlic grows a stiff flower stalk, the scape, and has fewer, larger cloves, usually 10 or fewer. It is generally hardier and has more flavour, but stores for less time. Types include Rocambole, Purple Stripe and Porcelain; ‘Music’, ‘German Red’ and ‘Spanish Roja’ are examples.
Softneck garlic is the supermarket type: more cloves, up to 18 or more, white papery skins, rarely a flower stalk, and the longest storage. Its soft necks can be plaited. Many softnecks prefer milder winters, though some, such as ‘Inchelium Red’, suit cold climates.
Elephant garlic isn’t true garlic but a kind of leek, with huge, mild cloves. It needs a long, warm season.
Match your climate. Varieties grown for mild regions often do poorly or turn very hot in cold ones (UW-Madison).
Garlic types compared
-
Hardneck: Rocambole
- Cloves per bulb
- 6 to 11
- Scape
- Tightly coiled
- Storage
- 3 to 4 months
- Notes
- Rich flavour; peels readily
-
Hardneck: Porcelain
- Cloves per bulb
- 4 to 6, large
- Scape
- Looping
- Storage
- 4 to 8 months
- Notes
- Tall; big cloves
-
Hardneck: Purple Stripe
- Cloves per bulb
- 8 to 12
- Scape
- Curling
- Storage
- A little longer than Rocambole
- Notes
- Purple-streaked skins
-
Softneck
- Cloves per bulb
- 10 to 40
- Scape
- Rarely
- Storage
- 6 to 9 months
- Notes
- Most productive; plaits well
-
Elephant
- Cloves per bulb
- 5 or 6, huge
- Scape
- Yes
- Storage
- Stores poorly
- Notes
- A leek, not a true garlic; mild
Figures from UW-Madison and Utah State. In cold winters a hardneck is the safer choice; for long storage, a softneck.
Where garlic grows best
Garlic wants a warm, sunny site with free-draining soil, and a spell of winter cold.
Cold. Most varieties need one to two months at 0 to 10 °C (32 to 50 °F) to form a good bulb (RHS). That is why garlic is planted in autumn: roots grow over winter and the tops grow fast in spring (Utah State).
Frost. Established plants are hardy; even leaves that come up in a mild spell tolerate temperatures down to about -7 °C (the 20s °F) (Iowa State). In very cold areas, mulch autumn plantings with straw.
Wet. Waterlogged winter soil makes garlic more prone to disease. On heavy, wet ground, start cloves in modules or plant on raised ridges.
Sun. Full sun: at least six hours a day, and UMD prefers eight to ten.
- Winter chill
- 1 to 2 months at 0 to 10 °C (32 to 50 °F)
- Sun
- At least six hours a day
- Soil
- Free-draining; never waterlogged
Soil
Garlic grows best in fertile, well-drained soil high in organic matter (Iowa State, Utah State).
Preparation. Weed, then dig in about two bucketfuls of well-rotted (not fresh) manure or garden compost per square metre (RHS). Heavy clay gives misshapen bulbs: work in organic matter to loosen it.
pH. Garlic dislikes very acid soil, below about pH 6. Lime in autumn or winter if a test shows you need to (RHS).
Rotation. Don’t follow onions, leeks or other alliums, and never plant where white rot has been.
Planting
Plant single cloves in autumn, pointed end up, 2.5 to 5 cm (1 to 2 in) below the surface.
Most garlic needs one to two months at 0 to 10 °C (32 to 50 °F) to form a good bulb, so plant in autumn.
When to plant garlic
Plant in autumn, so the cloves get their winter chill and grow roots before the ground freezes.
In the UK, plant from mid-autumn to early winter (RHS).
In the US, Utah State plants from mid-September to early November and Iowa State in October to early November; UMD plants in mid to late October. In cold Wisconsin, plant within a week or two after the first killing frost, so roots develop but shoots don’t emerge before the hard freeze (UW-Madison).
Spring planting. Some varieties can be planted in late winter or early spring, as soon as the soil can be worked. Bulbs are usually smaller (Utah State, Iowa State).
Heavy soil. Start cloves in modules in late autumn and plant out in spring.
- Plant cloves in autumn.
- Before the ground freezes.
- Spring planting gives smaller bulbs.
Starting garlic in modules
For heavy or wet soil: cloves root in modules over winter and go out in spring.
-
Fill modules or small pots
With peat-free multi-purpose compost.
-
Plant one clove per module
Pointed end up, with the tip about 2.5 cm (1 in) below the surface (RHS).
-
Keep them cold
In a cold frame or a sheltered spot outside, so they still get their winter chill.
-
Plant out in spring
Once the soil has dried out a little, disturbing the roots as little as possible.
How to plant garlic
Split the bulb just before planting and use the biggest cloves: they make the biggest bulbs.
-
Split the bulbs
Into single cloves, keeping the papery skin on. Discard soft, bruised or mouldy ones.
-
Point them up
Flat base down, pointed end up.
-
Plant at the right depth
With the tip about 2.5 to 5 cm (1 to 2 in) below the surface (RHS, UMD); deeper in light soil, which gives bigger bulbs, but not in heavy soil. In cold-winter areas, Utah State plants 5 to 7.5 cm (2 to 3 in) deep.
-
Space them
15 cm (6 in) apart in rows 30 cm (12 in) apart (RHS, Gardeners’ World). US extensions plant closer, 7.5 to 15 cm (3 to 6 in), in double or triple rows.
-
Cover against birds
With fleece or netting until the cloves are rooted firmly enough to resist pulling.
-
Mulch in cold areas
Iowa State lays 10 to 15 cm (4 to 6 in) of straw in November and pulls it between the rows as shoots appear in spring.
Care
Weed, water in dry spells in spring, feed as growth takes off, and snap off scapes.
Stop watering once the leaves start to yellow: wet soil at the end delays curing and spoils storage.
Care by growth stage
Autumn and winter
Protect: fleece or netting
Keep birds off; mulch in cold areas. See how to plant.
Early spring
Feed: from April · Weed: first two months matter most
Weed by hand and feed as growth takes off. See feeding.
Late spring
Water: about 2.5 cm (1 in) a week
Water in dry spells; snap off scapes. See scapes.
Leaves yellowing
Water: stop
Stop watering and get ready to lift. See harvesting.
End of season
Rotate: away from alliums
Cure and store the bulbs; keep the best for replanting. See saving planting stock.
Watering and mulching
Garlic has shallow roots, and drought in spring means smaller bulbs.
How much. About 2.5 cm (1 in) a week, rain included (Iowa State): in dry weather in spring and early summer, a thorough weekly watering. Utah State soaks the soil 30 cm (12 in) deep.
When to stop. As the leaves start to yellow. Wet soil at the end delays curing, spreads disease and stains the bulb skins (Iowa State, Utah State).
Mulch. Straw, shredded leaves or grass clippings between the rows hold moisture and smother weeds. In cold areas an autumn straw mulch protects against winter injury.
Weeding. By hand or with very shallow cultivation: hoeing can damage the shallow roots and bulbs.
Feeding garlic
Garlic needs more nutrients than many vegetables (Iowa State, UMD). Large tops make large bulbs.
Before planting, dig in compost or manure; without a soil test, Iowa State also works in a general fertiliser such as 10-10-10 at 0.5 to 1 kg per 10 m² (1 to 2 lb per 100 sq ft).
In spring, feed with nitrogen as strong growth begins: Gardeners’ World uses dried chicken manure pellets from April and stops in mid-May; Utah State side-dresses in mid-April and again in late May; Iowa State bands a general fertiliser beside the rows three to four weeks after shoots appear.
Scapes and flower stems
Hardneck garlic sends up a curling flower stalk, the scape, in late spring. Remove it, and the plant puts its energy into the bulb (Iowa State, UMD).
When. Once the scape has fully extended above the leaves and begun to curl, but before it straightens and the tip opens.
How. Snap or cut it off as low as you can without taking leaves.
Eat them. Young scapes have a mild garlic flavour: chop them into eggs, salads and stir-fries, or make pesto.
Softneck garlic rarely flowers. When it does, it is a sign of stress such as heat or drought: remove the stem (RHS).
Garlic in containers
Containers suit garlic where the soil is heavy or has had white rot.
Pot. At least 25 cm (10 in) deep (RHS), in peat-free multi-purpose compost. Gardeners’ World puts three cloves in a 20 cm (8 in) wide pot, five or six in a 30 cm (12 in) one.
Planting. Same depth as in the ground, with cloves closer together.
Care. Compost in pots dries out quickly: check it often, and feed in spring as for garden plants.
Problems
Birds, wet soil and rots are the usual troubles; most start at planting time.
Common garlic problems
Many problems start at planting: the wrong stock, the wrong time or wet ground.
Cloves pulled out of the ground
- Birds
Birds tug at newly planted cloves, especially shallow ones. Cover with fleece or netting until they are rooted.
Round bulbs with no cloves
- Rounds
Cloves too small, planted in late spring, or a poor season (Iowa State). Garlic also needs a spell of winter cold to form good bulbs (RHS). Plant large cloves in autumn.
Small bulbs
- Spring planting
- Drought
Spring planting, dry spring weather, crowding or too little food. Plant in autumn and water and feed in spring.
Split, open bulbs
- Late harvest
Lifted too late. Harvest as the leaves yellow, before they are completely dry.
Yellow leaf tips in spring
- Stress
Early yellow tips usually mean water stress, nutrient shortage or disease, and can cut yields (Iowa State).
Shoots up in midwinter
- Mild spell
A mild spell brings leaves up early. They tolerate frost, and cold weather usually halts growth again.
More problems with garlic
Common pests
Onion maggots
Larvae tunnel into bulbs. Rotate, avoid too much organic matter, and destroy affected plants (Utah State).
Thrips
Tiny insects that turn leaves silver or grey. Mulch and a strong spray of water help (Utah State).
More problems with garlic
Common diseases
White rot
Yellowing, wilting leaves near harvest time and a white fluffy fungus with tiny black specks on the bulb base. It persists in soil for years. Lift and bin affected plants, don’t compost them, avoid spreading soil on boots and tools, and grow garlic elsewhere or in pots.
Leek rust
Bright orange pustules on the leaves in summer, worst in wet weather. Rarely serious; the bulbs are safe to eat. Remove affected leaves, or lift and use the crop.
Storage rots
Watery decay inside stored bulbs. Plant only healthy cloves, dry the crop well, and handle bulbs gently.
Harvest & Use
Lift bulbs as the leaves yellow, cure them in the dry, and store them cool.
Harvesting garlic
Lift garlic when the leaves turn yellow: autumn-planted garlic from late spring to midsummer, spring-planted from midsummer to early autumn.
Signs. Iowa State starts when only five green leaves remain; UMD when about half the foliage has turned brown. Don’t wait until it is completely dry: late-lifted bulbs open up and store poorly.
How. Loosen the soil with a fork and lift the bulbs gently. Don’t pull them by the leaves, and don’t knock or bruise them.
Cure. Dry the whole plants for two to four weeks (RHS), laid out on racks somewhere warm, dry and airy. The RHS and Gardeners’ World dry them in the sun away from rain; UMD and Utah State in the shade. They are ready when the skins are papery and the roots dry.
- Lift as the leaves yellow.
- Loosen with a fork; don’t pull.
- Cure for two to four weeks.
Storing and using garlic
Trim. Once cured, cut the dry tops about 2.5 cm (1 in) above the bulb, trim the roots and brush off loose soil. Or plait softneck garlic by its leaves.
Where. Somewhere cool and dry, in a mesh bag, an open crate or hung in plaits. The RHS stores at 5 to 10 °C (41 to 50 °F); Iowa State at 0 to 4 °C (32 to 40 °F) and 65 to 70% humidity.
How long. Three to nine months, depending on type: eat hardnecks first, as softnecks keep longest.
Using it. Crush, slice or roast cloves whole; hardnecks have more flavour roasted.
Propagation
Saving your best bulbs as next year’s planting stock.
Saving your own planting stock
Garlic doesn’t grow reliably from seed; it is grown from cloves. Once you have a variety that does well, you can replant your own.
Choose the largest, firmest, healthiest bulbs, and keep them aside when you store the crop. Large cloves give the biggest bulbs.
Plant the separated cloves in autumn, as with bought stock. Never replant bulbs from a crop with white rot or virus.
Bulbils. Hardneck scapes left on the plant form small aerial cloves. Planted, they take two or three years to reach a usable size, first making single-clove rounds (UW-Madison, Iowa State).
More to Explore
Quick answers, guides that pair well with garlic, and the sources behind this one.
Frequently asked questions
When should I plant garlic?
In autumn, so the cloves get a winter chill. See when to plant.
How deep do I plant garlic cloves?
With the tip 2.5 to 5 cm (1 to 2 in) below the surface, pointed end up. See how to plant.
Can I plant supermarket garlic?
It isn’t recommended: it may carry disease, suit another climate, or be treated against sprouting.
Can I plant garlic in spring?
Yes, some varieties, but bulbs are usually smaller than from autumn planting.
Should I cut off garlic scapes?
Yes, for bigger bulbs, and eat them. See scapes.
When is garlic ready to harvest?
When the leaves turn yellow, before they are completely dry. See harvesting.
Why did my garlic make one round bulb?
Small cloves, late spring planting or a poor season. See common problems.
How long does garlic keep?
Three to nine months, cured and stored cool and dry. See storing garlic.
Is garlic toxic to pets?
Yes: the ASPCA lists it as toxic to dogs, cats and horses.
Related guides
Sources
- How to grow garlic (opens in a new tab) Royal Horticultural Society
- Garlic (opens in a new tab) ASPCA Animal Poison Control
- Growing garlic in the home garden (opens in a new tab) Iowa State University Extension and Outreach
- Growing garlic in a home garden (opens in a new tab) University of Maryland Extension
- Garlic in the garden (opens in a new tab) Utah State University Extension
- Garlic, Allium sativum (opens in a new tab) University of Wisconsin-Madison Extension
- How to grow garlic (opens in a new tab) BBC Gardeners’ World