Vegetable · Amaryllidaceae
Garlic
Allium sativum
Tuck one papery clove into fall soil and leave it be until summer, when a single segment fattens into a whole banded head.
Full sun
Every 3–7 days
240–270 days
USDA 3–8
Overview
Few crops give back so much for so little handling. One clove goes into autumn ground, and across the next eight or nine months it throws down roots through winter, unfurls flat blue-green strappy leaves in spring, and swells into a plump banded head by midsummer. It sits in the onion family, and that kinship reads all over it, from the flat blade of each leaf to the sharp reek it lends a cutting board.
Two builds split the gardener's choice. Hardneck plants throw up a stiff woody stalk and a slender flower stem that loops into a curling scape, hold for a few months, and take a hard winter in stride. Softneck plants leave off that central stalk, pack more cloves under the papery wrappers, keep far longer, and bend easily into a braid, which suits milder ground.
Nothing hurries garlic, and that is the fact to settle with. The clove needs a true stretch of winter cold before it will break apart into a segmented head, so the calendar, not any effort of yours, sets the tempo. Time the planting right and the rest comes down to mulch, a spring feed, and patience.
Care
The short version: set the fattest cloves point-up in fall in loose, crumbly, well-drained soil under full sun, hold the bed evenly moist while the strappy leaves climb in spring, feed nitrogen early, then let the ground dry so the papery bulbs firm up for lifting.
Light
Garlic reaches for full sun, ideally 6 or more hours a day, to pack out a fat bulb. It will scrape by in partial sun, but the heads come up smaller and the flat leaves thinner and weaker.
Water
Keep the ground evenly moist while the leaves climb in spring, about an inch of water a week, and never let it turn to sodden mud. Then back off and stop watering in the last 2 weeks before harvest, which lets the wrapped bulbs cure and firm for storage.
Soil
Give it loose, crumbly, well-drained loam with plenty of organic matter forked through, at a pH between 6.0 and 7.0. Where the ground packs into heavy clay, a raised bed keeps the papery bulbs from softening and rotting in the wet.
Temperature
Garlic stands a wide span of weather, roughly 14°F to 86°F (-10°C to 30°C), and it needs a real winter chill before a single clove will divide into a full head. That cold spell is the entire reason it goes into the ground in fall.
Humidity
Plain outdoor air suits garlic, so there is no target to hunt down. Good airflow counts for more, since damp, crowded leaves let orange rust and other fungal fuzz settle in.
Feeding
Fork compost or a balanced fertilizer into the bed at fall planting, then side-dress with nitrogen in early spring as the flat blades push up. Cut the feeding once the bulbs start to swell, around scape emergence, or you grow more leaf and less bulb.
Pruning
Garlic barely needs a knife. On hardneck plants, snap off the curling scapes soon after they arch up and loop, so the plant pours its strength into the bulb rather than the flower stalk, and the tender scapes make good eating.
Size & spacing
Plants stand 12 to 24 inches (30 to 60 cm) tall, all narrow upright blades. Set the cloves 6 to 12 inches (15 to 30 cm) apart so each has room to fatten and air can slip between the leaves.
When to plant
The clock, not the gardener, drives garlic. Slide the cloves into fall soil 4 to 6 weeks before the ground freezes so young roots grip before winter, hand the plant over to the cold, and pull the bulbs in mid to late summer once the lowest strappy leaves have gone brown and papery.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Fall, about 4-6 weeks before the ground freezes (typically late September through November depending on region), so cloves root before winter
- Harvest: Hardneck scapes appear in early summer and are removed; harvest bulbs in mid-to-late summer when the lower one-third to one-half of the leaves have yellowed and browned
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Garlic tells you what is wrong either in the flat leaves standing above ground or in the wrapped bulb you cannot see until you lift it. Read the leaf marks early and the crop often pulls through, while a soft rotting bulb needs pulling out fast. Match the look below, then move before it creeps down the row.
Yellowing plants with white fuzz and tiny black specks at the bulb base
This is white rot, a soilborne fungus that eats the bulb and can lurk in the ground for decades until the next allium comes along. Look for a cottony white fuzz creeping over the basal plate, studded with poppy-seed black sclerotia. No cure saves it mid-season, so dig out the sick plants with the soil around them and bin the whole lot, never the compost heap. The slower lookalike, fusarium basal rot, stains the base a pinkish white but carries none of those hard black specks.
Fix:
- Remove and destroy infected plants and surrounding soil; do not compost
- There is no effective in-season chemical rescue for home gardens
Orange rusty bumps on the leaves
Those raised orange blisters are garlic rust, a fungus that thrives in cool, humid, crowded rows and puffs a powdery dust of spores the moment you rub a flat leaf. Strip the worst-flecked foliage and open the spacing so moving air can dry the blades. If it lands late, lift the crop early, since the bulbs below are still perfectly good to eat.
Fix:
- Remove heavily infected foliage
- Harvest promptly if infection occurs late in the season; bulbs are still edible
Small bulbs that never split into cloves
A head that stays runty or refuses to break into cloves almost always missed its cold winter, set in too late in fall or shoved in come spring without enough rooting and chill. Weeds hemming in the sparse upright blades and a skipped spring nitrogen feed only make it worse. Cook the runts, then next time push the biggest cloves in 4 to 6 weeks before the ground freezes.
Fix:
- Use undersized bulbs in the kitchen; they are edible
- Adjust planting date and fertility the following season
Silvery streaks and a gray cast on the leaves in hot weather
Silvery flecking that spreads through hot, dry spells is the mark of onion thrips rasping at the leaf surface. Part the flat blades and hunt the folds for slender yellow-brown insects, or rap the foliage over white paper and watch them drop. Blast them off with a hard jet of water, bring in insecticidal soap if the flecking runs heavy, and keep the plants watered through the dry stretch.
Fix:
- Knock populations down with a strong spray of water
- Use insecticidal soap if damage is heavy, ensuring coverage in leaf axils
Toxicity
The same pungent bite that makes garlic a kitchen staple makes it genuinely dangerous to animals. Those organosulfur compounds tear into the red blood cells of cats, dogs, horses, livestock, rabbits, and birds, and can bring on hemolytic anemia whether the garlic is raw, cooked, or ground to powder. Cats take the hardest hit of all, and clove for clove garlic outpunches onion by weight, so keep every scrap of it far from pets and stock.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
Vomiting, diarrhea, drooling, dullness and weakness, pale gums, a racing heart and fast breathing, urine gone red or brown, and collapse as hemolytic anemia sets in; cats are hit even by a small taste.
Dogs Moderate
Vomiting, diarrhea, belly pain, dullness and weakness, pale gums, a quickened heart and breathing, and red or brown urine; a big or repeated dose can drive severe hemolytic anemia.
Horses Moderate
Weakness, dull dragging behavior, pale mucous membranes, and discolored urine from hemolytic anemia once a meaningful amount has been eaten.
Rabbits Toxic
Garlic has no business in a rabbit's diet. The same organosulfur compounds that harm cats and dogs strike a rabbit's red blood cells, and no amount is safe to offer, so keep every form well clear of the hutch.
Livestock Toxic
Cattle, sheep, goats, and horses that graze garlic or its trimmings can slide into hemolytic anemia, which surfaces as weakness, a dull manner, pale gums, and dark, discolored urine. Fence the stock out of the bed and never toss them allium scraps.
Birds Toxic
Garlic is unsafe for birds, backyard poultry and pet parrots alike. Even a small amount can wear down their red blood cells over time, so keep bulbs, loose cloves, and seasoned scraps out of reach.
People Safe
Garlic is a kitchen staple and safe for people to eat, raw or cooked. The threat that hangs over animals does not carry the same danger for us, so cook and enjoy it freely.
Store bulbs, peeled cloves, garlic powder, and garlic-seasoned foods where pets cannot reach them; fence or cover garden beds, and never feed pets table scraps containing garlic or onion. Signs of anemia can be delayed several days after ingestion.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Hundreds of garlic cultivars are out there, yet they fall into a handful of familiar hardneck and softneck shapes, the stiff-stalked and the pliable-necked. These are the ones you meet most.
Music
A hardneck porcelain type whose bulb holds 4 to 6 fat, easy-peeling cloves under bright white wrappers and shrugs off a brutal winter, a dependable pick up north.
German Extra Hardy
A hardneck porcelain type prized for standing up to deep cold and for a strong, full-bodied bite.
Inchelium Red
A softneck artichoke type, mild in flavor and crowded with cloves, that runs best in gentler climates and braids into a neat rope.
Silver Rose
A softneck silverskin type with rose-tinted cloves under pale wrappers that keeps longer than nearly any other garlic and is a classic for braiding.
Companions
Garlic earns its keep as a neighbor, since its sulfur compounds help drive off aphids and other soft-bodied pests, but it sets back the legumes, so keep it clear of beans and peas.
Plant near
roses: Garlic's sulfur compounds are reported by extension sources to help deter aphids and other soft-bodied pests around roses
brassicas (cabbage family): Interplanted garlic can help repel some cabbage-family insect pests
carrots: Garlic may help deter carrot pests such as rust fly, and the crops do not compete strongly
Keep apart
beans: Alliums are reported to inhibit the growth of beans and other legumes
peas: Alliums are reported to inhibit the growth of peas and other legumes
How to propagate
Garlic copies itself straight from its own cloves, which makes starting it about as plain as growing gets, though the wrapped segments pay you back only on their own unhurried timetable.
Bulbs & cormsEasy
Fall, 4-6 weeks before the ground freezes · Roots establish in 4-8 weeks before the ground freezes; bulbs are ready to harvest about 8-9 months after planting
Garlic grows from cloves, not seed, so crack a head into its segments just before planting and leave the papery wrapper on each one. Push the biggest cloves in pointed end up, about 2 inches deep and 4 to 6 inches apart, 4 to 6 weeks before the ground freezes, then mulch once the soil cools so they set roots over the next month or two ahead of winter. Waiting is the real price, since the bulbs will not lift until 8 to 9 months later in mid to late summer. You can also sow the little topset bulbils from hardneck scapes, but they need 2 to 3 seasons to swell into full heads.
Myths
Garlic is a safe, natural flea and tick remedy for dogs and cats.
This one is truly dangerous. Garlic poisons cats and dogs in every form, since its thiosulfates wreck red blood cells and can set off Heinz-body hemolytic anemia, and cats suffer worst. No dose is safe or proven to work against parasites, so reach for a vet-approved product instead.
Grocery-store garlic works fine as planting stock.
Supermarket heads are often dosed with sprout inhibitors, can carry disease, and tend to be a variety that never suited your climate. Plant certified disease-free seed garlic from a trusted supplier and you begin with clean, sound cloves.