Vegetable · Amaryllidaceae
Garlic
Allium sativum
Plant a clove in fall and forget about it until summer, when one bulb becomes a whole head.
Full sun
Every 3–7 days
240–270 days
USDA 3–8
Overview
Garlic is one of the most rewarding crops for how little it asks. You plant a single clove in autumn, and over the next eight or nine months it roots through winter, pushes up green leaves in spring, and swells into a full head by midsummer. It belongs to the onion family, and that kinship shows in everything from its flat leaves to its pungent kitchen punch.
Gardeners pick between two camps. Hardneck types send up a stiff central stalk and a curling flower stem called a scape, store for a few months, and handle hard winters with ease. Softneck types skip the stalk, carry more cloves per bulb, keep far longer, and braid up neatly, which suits milder regions better.
There is no rushing garlic, and that is the one thing to make peace with. The plant needs a real winter chill to split a clove into a proper head, so the calendar, not your effort, sets the pace. Get the timing right and the rest is mostly mulch, a spring feed, and patience.
Care
The short version: plant the biggest cloves in fall in loose, fertile, well-drained soil and full sun, keep the bed evenly moist through spring growth, feed nitrogen early, then ease off the water as the bulbs cure for harvest.
Light
Garlic wants full sun, ideally 6 or more hours a day, to build a big bulb. It will limp along in partial sun, but the heads come out smaller and the plants weaker.
Water
Keep the soil evenly moist through spring growth, about an inch of water a week, without ever letting it sit waterlogged. Then ease off and stop watering in the last 2 weeks before harvest, which helps the bulbs cure and store well.
Soil
Plant in loose, fertile, well-drained loam with plenty of organic matter worked in, and a pH between 6.0 and 7.0. If your ground is heavy clay, a raised bed keeps the bulbs from rotting in wet soil.
Temperature
Garlic is hardy across a wide range, from about 14°F to 86°F (-10°C to 30°C), and it needs a real winter chill to split a clove into a full head. That cold spell is the whole reason it goes in the ground in fall.
Humidity
Ordinary outdoor humidity suits garlic fine, so there's no level to chase. Good airflow matters more, since damp, crowded leaves invite rust and other fungal trouble.
Feeding
Work compost or a balanced fertilizer into the bed at fall planting, then side-dress with nitrogen in early spring as the leaves push. Stop feeding by the time the bulbs start to form, around scape emergence, or you grow leaves at the bulb's expense.
Pruning
Garlic needs almost no pruning. On hardneck types, snap off the scapes soon after they emerge and curl, so the plant pours its energy into the bulb instead of the flower stalk, and the scapes themselves are good eating.
Size & spacing
Plants reach 12 to 24 inches (30 to 60 cm) tall with narrow upright leaves. Set the cloves 6 to 12 inches (15 to 30 cm) apart so each one has room to size up and air can move between them.
When to plant
Garlic runs on the calendar. Plant the cloves in fall, 4 to 6 weeks before the ground freezes, so they root before winter, then let the cold do its work and lift the bulbs in mid to late summer once the lower leaves have browned.
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
Most garlic trouble shows in the leaves above ground or the bulb you only see at harvest. Catch the leaf signs early and you can often save the crop, while bulb rots call for fast removal. Match what you see below, then act before it spreads down the row.
Yellowing plants with white fuzz and tiny black specks at the bulb
This is white rot, a soilborne fungus that rots the bulb and can sit in the ground for decades waiting for the next allium. There is no in-season rescue, so lift the affected plants and the soil around them and bin the lot rather than composting it. The slower-moving lookalike is fusarium basal rot, which shows a pinkish-white stain but none of the poppy-seed black sclerotia.
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 pustules are garlic rust, a fungus that loves cool, humid, crowded plantings and dusts powdery spores when you rub a leaf. Strip the worst foliage and give plants room so air can dry the leaves. If it hits late in the season, harvest early, since the bulbs underneath are still 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 bulb that stays small or refuses to divide usually means it missed its cold winter, planted too late in fall or pushed in during spring without enough rooting and chill. Weeds crowding the sparse upright leaves and skipping the spring nitrogen feed make it worse. Use the runts in the kitchen, then plant the largest cloves 4 to 6 weeks before the ground freezes next time.
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 in hot, dry spells points to onion thrips rasping at the leaf tissue. Part the leaves and look in the folds for tiny slender yellow-brown insects, or tap the foliage over white paper to see them drop. Blast them off with a strong jet of water, reach for insecticidal soap if the damage is heavy, and keep plants watered through dry stretches.
Fix:
- Knock populations down with a strong spray of water
- Use insecticidal soap if damage is heavy, ensuring coverage in leaf axils
Toxicity
Garlic is a kitchen staple for people but genuinely dangerous for animals. The same organosulfur compounds that give it flavor attack the red blood cells of cats, dogs, horses, livestock, rabbits, and birds, and can cause hemolytic anemia in every form, raw, cooked, or powdered. Cats are the most sensitive of all, and garlic is more potent than onion by weight, so keep all of it well away from pets and stock.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
Vomiting, diarrhea, drooling, lethargy, weakness, pale gums, rapid heart rate, elevated respiratory rate, red or brown discolored urine, collapse from hemolytic anemia; cats are especially sensitive even to small amounts
Dogs Moderate
Vomiting, diarrhea, abdominal pain, lethargy, weakness, pale gums, elevated heart and respiratory rate, red or brown urine; large or repeated doses can cause severe hemolytic anemia
Horses Moderate
Weakness, lethargy, pale mucous membranes, and discolored urine from hemolytic anemia after ingesting significant quantities
Rabbits Toxic
Garlic has no place in a rabbit's diet. The same organosulfur compounds that harm cats and dogs attack a rabbit's red blood cells, and there is no safe amount to offer, so keep every form well away from them.
Livestock Toxic
Cattle, sheep, goats, and horses grazing on garlic or its trimmings can develop hemolytic anemia, which shows up as weakness, a dull manner, pale gums, and dark, discolored urine. Fence stock out of the bed and never toss them allium scraps.
Birds Toxic
Garlic is unsafe for birds, including backyard poultry and pet parrots. Even small amounts can break down their red blood cells over time, so keep bulbs, cloves, and seasoned scraps out of reach.
People Safe
Garlic is a kitchen staple and safe for people to eat, raw or cooked. The toxicity that threatens animals does not carry the same risk 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 exist, but they sort into a few familiar hardneck and softneck types. These are the ones you will run into most.
Music
A hardneck porcelain type that carries 4 to 6 big, easy-to-peel cloves per bulb and shrugs off hard winters, which makes it a dependable choice up north.
German Extra Hardy
A hardneck porcelain type grown for its toughness through cold winters and its strong, full flavor.
Inchelium Red
A softneck artichoke type with mild flavor and plenty of cloves that does best in milder climates and braids up well.
Silver Rose
A softneck silverskin type with rose-tinted cloves that stores longer than almost any other garlic and is a traditional pick 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 multiplies from its own cloves, which makes it about as simple as planting gets, though it pays you back on its own slow schedule.
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 break a bulb into its cloves just before planting and leave the papery wrappers on each one. Push the largest 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 root over the next month or two before winter. Patience is the real cost here, since the bulbs aren't ready to lift until 8 to 9 months later in mid to late summer. You can also plant the little topset bulbils from hardneck scapes, but they take 2 to 3 seasons to size up into full bulbs.
Myths
Garlic is a safe, natural flea and tick remedy for dogs and cats.
This one is genuinely dangerous. Garlic is toxic to cats and dogs in every form, because its thiosulfates damage red blood cells and can bring on Heinz-body hemolytic anemia, and cats are hit hardest. 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 garlic is often treated with sprout inhibitors, can carry disease, and tends to be a variety that never suited your climate. Plant certified disease-free seed garlic from a reputable supplier and you start clean.