Vegetable · Amaryllidaceae
Garlic
Allium sativum
Slip a clove into the ground in fall and basically forget about it until summer, when that one clove turns into a whole head.
Full sun
Every 3–7 days
240–270 days
USDA 3–8
Overview
For how little it asks of you, garlic pays back like few other crops. Drop a single clove in the ground in autumn and, over the next eight or nine months, it roots through winter, throws up green leaves in spring, and fattens into a full head by midsummer. It's part of the onion family, and you can see that family resemblance in everything from those flat leaves to the sharp kick it brings to the kitchen.
You've got two camps to choose from here. Hardneck kinds push up a stiff central stalk and a curling flower stem called a scape, keep for a few months, and take hard winters in stride. Softneck kinds skip that stalk, pack more cloves into each bulb, hold far longer, and braid up nicely, which makes them a better fit for gentler climates.
There's no hurrying garlic, and that's really the one thing you have to come to terms with. The plant needs an honest winter chill to break a clove into a proper head, so it's the calendar setting the pace, not how hard you work at it. Nail the timing and the rest is mostly mulch, a spring feed, and patience.
Care
The short version: pop the biggest cloves in the ground in fall in loose, rich, well-drained soil and full sun, keep the bed evenly moist while it grows in spring, feed nitrogen early, then back off the water so the bulbs can cure up for harvest.
Light
Garlic is after full sun, ideally 6 or more hours of it a day, so it can pack on a big bulb. It'll get by in partial sun, sure, but you'll end up with smaller heads and weaker plants.
Water
Keep that soil evenly moist all through spring growth, roughly an inch of water a week, and never let it turn into a bog. Then back off and quit watering in the last 2 weeks before harvest, which lets the bulbs cure up and store well.
Soil
Give garlic loose, fertile, well-drained loam with a good helping of organic matter mixed in, and a pH somewhere between 6.0 and 7.0. Got heavy clay? A raised bed keeps the bulbs from sitting and rotting in soggy ground.
Temperature
Garlic shrugs off a wide range, roughly 14°F to 86°F (-10°C to 30°C), and it counts on a genuine winter chill to split a clove into a full head. That cold snap is the whole reason it goes in the ground come fall.
Humidity
Everyday outdoor humidity suits garlic just fine, so there's no number to chase. What counts more is good airflow, since damp, crowded leaves are an open door for rust and other fungal headaches.
Feeding
Mix compost or a balanced fertilizer into the bed at fall planting, then side-dress with nitrogen early in spring as the leaves come up. Ease off feeding once the bulbs start forming, right around scape emergence, or you'll just be growing leaves at the bulb's expense.
Pruning
Garlic barely needs any pruning at all. On hardneck kinds, snap off the scapes soon after they show up and curl, so the plant sends its energy into the bulb instead of the flower stalk, and those scapes are tasty in their own right.
Size & spacing
Plants stretch to 12 to 24 inches (30 to 60 cm) tall with slim upright leaves. Space the cloves 6 to 12 inches (15 to 30 cm) apart so each has room to size up and air can flow between them.
When to plant
Garlic goes by the calendar, plain and simple. Get the cloves in during fall, 4 to 6 weeks before the ground freezes, so they can root before the cold arrives, then just let winter do its thing and pull the bulbs in mid to late summer once those lower leaves have gone brown.
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
Almost every garlic hiccup turns up either in the leaves you can see or the bulb you can't until you dig it. Spot the leaf clues early and you can usually rescue the crop, though a rotting bulb means pulling it fast. Find the match below, then jump on it before it works its way down the row.
Yellowing plants with white fuzz and little black specks down at the bulb
You're looking at white rot, a soilborne fungus that rots the bulb and can linger in the ground for decades, just waiting for the next allium to show up. There's no saving it mid-season, so lift the affected plants along with the soil around them and bin the whole lot instead of composting. Its slower lookalike is fusarium basal rot, which leaves a pinkish-white stain but none of those 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
Rusty orange bumps showing up on the leaves
Those raised orange pustules are garlic rust, a fungus that loves it cool, humid, and crowded, and puffs out powdery spores when you rub a leaf. Pull off the worst foliage and open things up so air can dry the leaves. If it hits late in the season, just harvest early, because the bulbs down 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 bother to split into cloves
When a bulb stays small or won't divide, it usually missed out on its cold winter, either planted too late in fall or pushed in during spring without enough time to root and chill. Weeds crowding those sparse upright leaves and skipping the spring nitrogen feed only pile on. Use the runts up in the kitchen, then next time plant your largest cloves 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 when it's hot
Silvery flecking that spreads during hot, dry spells is a sign of onion thrips rasping away at the leaf tissue. Part the leaves and peek into the folds for tiny slender yellow-brown insects, or tap the foliage over white paper and watch them drop. Knock them off with a strong jet of water, grab insecticidal soap if the damage is bad, and keep the plants watered through the 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 sits in nearly every kitchen, yet it's honestly dangerous for animals. Those same organosulfur compounds that make it taste so good go after the red blood cells of cats, dogs, horses, livestock, rabbits, and birds, and they can trigger hemolytic anemia no matter the form, raw, cooked, or powdered. Cats feel it worst of all, and garlic packs more punch than onion pound for pound, so keep every bit of it well clear of pets and stock.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
Vomiting, diarrhea, drooling, lethargy, weakness, pale gums, a racing heart, faster breathing, red or brown discolored urine, and collapse from hemolytic anemia; cats are especially sensitive, and even a little can do it.
Dogs Moderate
Vomiting, diarrhea, belly pain, lethargy, weakness, pale gums, a quicker heart and breathing rate, and red or brown urine; large or repeated helpings can bring on severe hemolytic anemia.
Horses Moderate
Weakness, lethargy, pale mucous membranes, and discolored urine from hemolytic anemia after a horse eats a meaningful amount.
Rabbits Toxic
Garlic has no business in a rabbit's diet. The same organosulfur compounds that hurt cats and dogs go after a rabbit's red blood cells too, and there's no safe amount to offer, so keep every form of it well away.
Livestock Toxic
Cattle, sheep, goats, and horses that graze on garlic or its trimmings can end up with hemolytic anemia, showing 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 isn't safe for birds, backyard poultry and pet parrots alike. Even small amounts can wear 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 perfectly safe for people to eat, raw or cooked. The toxicity that endangers animals just doesn't carry the same risk for people, so go ahead and cook with 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
There are hundreds of garlic cultivars out there, but they really boil down to a handful of familiar hardneck and softneck kinds. Here are the ones you're most likely to meet.
Music
A hardneck porcelain type that packs 4 to 6 big, easy-to-peel cloves into each bulb and laughs off hard winters, which makes it a reliable pick if you're up north.
German Extra Hardy
A hardneck porcelain type prized for toughing out cold winters and for its strong, full-bodied flavor.
Inchelium Red
A softneck artichoke type with mild flavor and lots of cloves that's happiest in milder climates and braids up beautifully.
Silver Rose
A softneck silverskin type with rose-tinted cloves that keeps longer than just about any other garlic and is a classic choice 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 just replants itself from its own cloves, so growing more is about as easy as it gets, even if it pays you back on its own unhurried timeline.
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 comes from cloves, not seed, so break a bulb apart into its cloves right before planting and leave the papery wrapper on each one. Push the biggest cloves in pointy 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 can root over the next month or two ahead of winter. The real price here is patience, since the bulbs won't be ready to lift until 8 to 9 months later in mid to late summer. You can also plant those little topset bulbils off the hardneck scapes, but they take 2 to 3 seasons to grow into full bulbs.
Myths
Garlic makes a safe, natural flea and tick treatment for dogs and cats.
This one's actually dangerous. Garlic is toxic to cats and dogs in every form, since its thiosulfates damage red blood cells and can bring on Heinz-body hemolytic anemia, and cats take the hardest hit. No dose is safe or proven to work against parasites, so grab a vet-approved product instead.
Grocery-store garlic does the job just fine as planting stock.
Supermarket garlic is often treated with sprout inhibitors, can be carrying disease, and tends to be a type that never suited your climate anyway. Plant certified disease-free seed garlic from a good supplier and you're starting off clean.