A close relative of the onion, garlic is an edible, bulbous plant native to Asia that has been cultivated for several thousand years. Above ground, garlic appears as flattened, grass-like leaves (also known as scapes). In contrast, below ground, it forms a firm bulb, typically containing between four and 20 cloves, encased in a papery exterior.
Garlic should be planted in the fall, about a month or so before the first frost. Harvesting garlic is not an exact science. It will grow slowly over the next nine months or so and will deliver a bountiful harvest by mid-spring or summer. Garlic is known to be toxic to animals.
|Botanical Name||Allium sativum|
|Plant Type||Bulb, vegetable|
|Size||12 to 18 in. tall, 6 to 12 in. wide|
|Sun Exposure||Full sun|
|Soil Type||Moist, well-drained|
|Soil pH||Slightly acidic to neutral (6.0 to 7.0)|
|Hardiness Zones||4-9 (USDA)|
|Toxicity||Toxic to animals|
How to Plant Garlic
When to Plant
Garlic is planted either in the fall or the spring, depending on your climate. In the north, plant garlic in the fall before the first frost. It is best to plant garlic in early spring in warmer climates, though seed garlic must be chilled first to break it out of its dormant state.
When planting in fall, start as soon as the soil temperature has dropped to 60 degrees Fahrenheit. If you wait too long, the roots will not be able to prevent the plants from heaving upward when the soil freezes. You can help to prevent heaving by covering the plants with 3 to 4 inches of straw mulch.
Selecting a Planting Site
Choose a site with full sun and moist, well-drained, loose, and sandy conditions. Loose soil lets the bulbs grow easily without rotting from heavier and wetter soil or damaging the papery skin that protects the garlic bulb from rot.
When selecting a site for planting garlic, make sure it has not had onions or other alliums growing there in the previous season, and, ideally, not for at least three years. You do not want your garlic to have to fight for nutrients with other alliums that may be still trying to grow.
Space, Depth, and Support
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.
Dig holes in the ground that are around 2 to 3 inches deep to plant your garlic cloves. Space holes 4 to 6 inches apart. If planting in rows, space each row 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.
Plant the cloves 2 inches deep, placing each clove in its hole with the pointy tip facing up and the basal/root end facing down. Fill the planting hole with soil and pat it down gently. Top with 3 inches of mulch and water lightly. You should see garlic scapes emerge in about six to eight weeks.
While it may be surprising for a plant that grows primarily underground, garlic loves light. To ensure 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 to start with nutrient-rich soil. It should also be moist but well-draining, with an ideal pH of 6.0 to 7.0. It helps to add a layer of mulch atop your soil after planting 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 about a month before the first hard frost in 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. Mix a slow-release organic fertilizer 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.
Types of Garlic
The many sub-varieties of garlic fall into two basic categories: hardneck and softneck. Softneck varieties are best grown in warm climates, while hardneck is the garlic of choice for northern growers. Softneck garlic stores and travels better than hardneck garlic, and it 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.
Hardneck garlic is so named for its stiff central stalk, or neck. It typically produces fewer cloves compared to softneck bulbs. The cloves tend to be all one size, forming a circle around the plant's neck. Popular varieties include:
- Rocambole: Has very thin skin that peels easily, but bulbs don't store as long as other types. Also called serpent garlic, due to its curling scapes, this is one of the most widely grown varieties
- Purple striped garlic: Includes several striped varieties with flavors ranging from mild to pungent; Starbright is prized for its nutty flavor and storage quality, and Chesnok is good for roasting
- Porcelain garlic: Bulbs have only a few large cloves and thick skin that helps them store well. Georgian crystal is a mild variety, and Romanian red is spicy hot and tangy
Softneck garlic transports and store well and is the type most commonly sold at supermarkets.
- Artichoke: Commonly grown commercially. It is identifiable by its two concentric rows of cloves (and its resistance to peeling). Red Toch has cloves striped with red and pink and a balanced flavor
- Silverskin: Named for its silvery-white skin, the bulbs have numerous small cloves and a sturdy neck that is good for braiding. Most types have a stronger flavor than artichoke types. Two bold and full-flavored varieties are Nootka Rose and Rose du Var.
Garlic vs. Wild Garlic
Garlic and wild garlic (Allium ursinum) are often confused, not because of any physical attributes—the two plants look nothing alike—but by name and taste alone. Garlic bulbs may also grow greens, but wild garlic is a foraged bulbous perennial flowering plant and a relative of chives that grows wild in damp woodlands and is often found in marshlands. Both are culinary favorites, but wild garlic is much milder in taste than garlic. Many people use wild garlic in place of leeks, wild leeks (also called ramps), or scallions in a recipe.
You'll know it's time to harvest your garlic when the majority of the bottom leaves have turned brown, which usually happens by mid to late summer, but you may be able to do this in the spring, too. 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. Use caution because garlic bruises easily.
Brush off any soil clinging to the bulbs. Allow the bulbs to cure or dry for three to four weeks in either a well-ventilated room or a dry, shady spot outside. Once the tops and roots have dried, they can be cut off. You can also further clean the bulbs by removing the outer skins. Just be careful not to expose any of the cloves.
Harvested garlic likes to be stored in cool temperatures, as low as 32 degrees Fahrenheit. The softneck varieties may last up to eight months. Hardneck varieties may dry out, sprout or go soft within two to four months. Keeping hardnecks at 32 degrees Fahrenheit sometimes helps them survive for up to seven months without deteriorating.
How to Grow Garlic in Pots
If you want to try growing a hard-to-find garlic variety, try growing garlic in containers. Plant garlic in containers at the same time you would plant garlic in the ground: before the first freeze when the soil is cool. Choose a large container of any material with lots of drainage holes, or use a large grow bag. Fill it with high-quality potting mix, a slow-release fertilizer, and place cloves in the mix with the pointy end up. Keep the pot in a spot with six hours of direct sunlight, keep the soil moist but not soggy, and you'll be on your way to harvesting scapes and bulbs.
Many garlic growers recommend cutting off the scapes, or topsets, of the garlic plants as soon as they start to curl, to conserve energy for the bulbs. Others prefer to leave the scapes intact because they feel it helps the bulbs in storage. Some take a middle-ground approach and cut off the scapes before they turn woody, when they are still good for cooking.
There is nothing easier to propagate than garlic. Simply put aside a few top-quality bulbs to plant in the ground or in a container the next season. Store bulbs for replanting at room temperature, with fairly high humidity of about 70 percent.
Garlic planted in the fall will naturally overwinter to be ready for a spring or summer harvest. The best way to overwinter your garlic plants is to water the plants well after planting and then cover them with 6 inches of straw mulch. The mulch will keep the ground moist, stop soil heave, and stop the growth of spring weeds.
Common Pests and Plant Diseases
While a fairly hardy crop, garlic does have to contend with a few pests and diseases throughout its lifespan.
Nematodes can be a 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.
White rot fungus, which typically develops in the middle of the season, is among the most serious diseases garlic can face. 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.
Is garlic easy to grow?
Garlic is more popular today than ever and with good reason—it is packed with flavor and for the novice home gardener, it is easy to grow, making it the ideal introduction to edible crops. 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.
Can garlic grow indoors?
You can grow cloves indoors in pots that will result in garlic greens you can use for cooking. Plant three or four cloves in a medium pot (8 to 12 inches should work) of any material that's filled with potting soil, put the pot in a sunny window, lightly water, and you'll see greens that can be snipped growing in about a week. Cloves dry up after sprouting greens so just repeat the process.
Is garlic a good companion plant?
Garlic is a popular companion plant because it deters many pests and contains a naturally occurring fungicide that can help prevent diseases. Many other vegetables can be grown alongside garlic, including tomatoes, peppers, potatoes, carrots, and spinach. However, garlic and other alliums can stunt the growth of some plants, including beans, peas, sage, parsley, and asparagus.
Can I grow garlic from grocery store bulbs?
Sometimes garlic from a grocery store is treated to prevent sprouting. It's always best to buy good-quality garlic bulbs from other sources, such as a local farmer's market, nursery, or from a garden shop online.
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