A close relative of the onion, garlic is an edible, bulbous plant native to Asia that has been cultivated for several thousand years. It is more popular today than ever and with good reason—for the home gardener, it's quite easy to grow a year's supply, and you can give your leftover crop to friends and neighbors.
Above ground, garlic appears as flattened, grass-like leaves (also known as scapes), while below ground it forms a firm bulb, typically containing between four and 20 cloves, and encased in a papery exterior. Garlic should be planted in the fall, about a month or so before the first frost. It will grow slowly over the next nine months and will deliver a bountiful harvest by mid-spring.
|Botanical Name||Allium sativum|
|Mature Size||12–18 in. tall, 6–12 in. wide|
|Sun Exposure||Full sun|
|Soil Type||Moist but well-drained|
|Soil pH||Neutral to acidic|
|Flower Color||Pink, white|
|Hardiness Zones||4–9 (USDA)|
|Toxicity||Toxic to dogs and cats|
Garlic is an exceptionally easy-to-grow plant, making it the ideal entryway into edible crops for many notice gardeners. It's almost impossible to not score a bountiful harvest on your first go at it, as long as you maintain the proper (minimal) conditions it requires. Garlic will grow best in moist but well-draining soil and in a sunny position in your yard. Though it grows slowly, you will be able to harvest it in early spring, clearing space in your garden for more plants throughout the desirable spring and summer growing season.
While it may be surprising for a plant that grows primarily underground, garlic loves light. In order for the best chance at growing success, plant your garlic in a spot that receives full sunlight for at least six to eight hours a day.
One of the most important factors in successfully growing garlic is possessing nutrient-dense soil. The soil you plant your garlic in should be moist but well-draining, with a neutral-to-acidic pH level. You can also add a layer of mulch atop your soil after planting in order to safeguard the bulbs, conserve moisture, and prevent the growth of weeds.
True to its easy-going nature, garlic doesn't have a ton of water requirements. It generally likes its soil moist and should receive around an inch of water per week, with a slight increase if the weather is especially warm. Keep the soil evenly moist throughout the first part of the growing season, but allow the soil to go dry for two or three weeks before harvesting—if conditions are too wet near harvest time, mold can grow.
Temperature and Humidity
Garlic is a very hardy plant, and it actually grows best through the colder winter months. That being said, be sure to plant your garlic seed about a month before the first hard frost each fall. Additionally, garlic has no special humidity requirements—it is often already harvested before the peak of summer heat and humidity.
The use of fertilizer can be beneficial when growing garlic. To use, mix in slow-release organic blend into your soil as you plant your garlic in the fall. Then, when the leaves begin to grow in the spring, feed the soil surrounding your plantings with a fertilizer blend high in nitrogen.
Is Garlic Toxic?
Though edible for humans, garlic is very poisonous to dogs and cats. The lethality of garlic depends on the amount ingested and the breed/size of the animal, but it almost always will lead to some sort of reaction. Members of the allium family (including onions, chives, and leeks as well) can even be responsible for severe toxicity that causes red blood cell destruction. If you notice your pet exhibiting any of the symptoms below, contact an emergency vet immediately.
Symptoms of Poisoning
- Irritation around the mouth
- Excessive drooling
- Red urine
- Wobbly gait
- Increased heart rate
- Difficulty breathing or panting
- Pale gums
The many sub-varieties of garlic fall into two basic categories: hardneck and softneck. Hardneck garlic includes the varieties of porcelain garlic, rocambole garlic, and purple stripe garlic. The softneck garlic varieties include artichoke garlic, silverskin garlic, and creole garlic.
A few basic differences exist between the two categories of garlic: Softneck varieties are best grown in warm climates, while hardneck is the garlic of choice for northern garlic growers. Softneck garlic stores and travels better than hardneck garlic, has a stronger flavor, and generally produces larger cloves. If you want a milder garlic taste, try elephant garlic—it's actually more closely related to leeks than it is to true garlic.
How to Grow Garlic From Seed
Garlic is planted either in the fall or the spring, depending on your climate. In the north, plant garlic in the fall. In warmer climates, it is best to plant garlic in early spring, though seed garlic must be chilled first to break it out of its dormant state.
To plant, start by separating the garlic bulbs into individual cloves, leaving the papery layer around each clove intact. Choose the largest cloves for planting and use the smaller ones for cooking or preserving. Plant the cloves 2 inches deep, placing each clove into its planting hole with the pointy tip facing up and the basal/root end facing down.
Space the cloves 4 to 6 inches apart in rows spaced about 2 inches apart. If you're tight on space, you can plant the cloves and rows closer together, but know that your bulbs will inevitably be smaller. Fill the planting hole with soil and pat it down gently. Top with mulch and water lightly.
As it grows, hardneck garlic produces a curly green scape. Harvest garlic scapes as soon as you notice them growing so that the plant concentrates its energy into growing a larger bulb rather than a flower stalk.
You'll know it's time to harvest your garlic when the majority of the bottom leaves have turned brown— this usually happens by mid-to-late summer. Dig up a test bulb or two to determine maturity—the garlic should be well-wrapped but not split.
To harvest, push a garden fork straight down into the soil about 6 to 8 inches away from the plant. Angle the fork so that it goes under the bulb and lifts it out of the ground. Don’t pull the bulb out by its leaves, or you risk breaking the bulb off and use caution, as garlic bruises easily.
Common Pests and Diseases
While a fairly hardy crop, garlic does have to deal with a few pests and diseases throughout its lifespan. White rot fungus, which typically develops in the middle of the season, is among the most serious diseases garlic can be dealt. It infects the plants, turning the leaves yellow and causing them to wilt and die back. As the roots rot, infected plants can uproot easily. Be sure you obtain cloves from certified disease-free stock because once a field has been infected with white-rot fungus, it can take decades for the infection to completely clear.
Nematodes are another chronic problem for garlic. These microscopic worm-like creatures live inside the garlic plant itself, eating it while reproducing. Nematodes don't need water to survive and can live in the surrounding soil for several years. A nematode infestation can build up for several seasons without much damage, and then strike and take out an entire crop. To control nematodes, make an effort to plant clean stock, inspect growing plants frequently, and remove any plants that look diseased.
Onion thrips have also been known to plague garlic. Thrips have rasping-sucking mouth parts that first damage the leaves then suck up the seeping plant fluid. Severe damage can cause the garlic plant to wilt and die. To control thrips, keep areas free of moist, wet mulch that provides breeding areas, and trap the insects with sticky traps.