Growing Garlic: A Garden Superhero

Growing garlic in your dome greenhouse or garden is easy and fun.

• Family: Amaryllidaceae
• Botanical Name: Allium sativum
• Common Name: Garlic
• Type: Bulb, vegetable
• Zone: 4-9 (USDA)
• Soil pH: Slightly acidic to neutral. 6.0 to 7.0
• Size: 12 to 18 in. tall, 6 to 12 in. wide

Growing Garlic

Growing garlic is simple and is a rewarding crop to grow. Besides the many uses in the kitchen, it is also a great companion plant in your garden.

There are two varieties of garlic: hardneck and softneck. Hardneck is best grown in a cooler climate whereas softneck is a warm climate garlic. If you will be growing your garlic in your greenhouse dome, softneck is the best option as they thrive in milder winters. We have grown hardneck garlic in the perimeter beds on the outside of our domes and softneck garlic inside the dome.     

Best Location in a Dome Greenhouse for Growing Garlic

Garlic needs full sun so be sure to plant your garlic in an open, unshaded area in your dome. It is a heavy feeder so test your soil and amend it as needed. Fertilize when necessary and be sure to keep the growing area weed-free so your garlic doesn’t have to compete with weeds for nutrients. You can grow softneck varieties outside in colder climates if you mulch them correctly.

Growing Garlic: Hardneck or Softneck?

So what is the difference between the two types of garlic, hardneck and softneck? The term “neck” refers to the growth from the center of the plant. Hardneck varieties grow a stalk that will produce a scape; an edible stem that flowers at the end of the season. Pickle your scapes or add them to recipes and salads. Harvesting the scape before it flowers allows the plant to put its energy into growing the bulb. 

Softneck varieties do not produce scapes, but they are great for braiding. The center of the plant produces leaves rather than a stalk and they are flexible when mature. They also have a longer storage life and are milder in flavor when roasted; this makes them popular with grocers. You can grow softneck varieties outside in colder climates if you mulch them correctly. Softneck garlic prefers hot summers and mild winters.

Hardneck garlic grows well outdoors in northern climates and also needs full sun with rich, composted soil that drains well. Hardneck varieties need about 4-6 weeks of cold temperatures under 40 degrees F for the bulbs to develop; this is called vernalization. Hardneck garlic needs to go through the vernalization process to grow and develop properly. 

Softneck garlics are not as particular about vernalization and that is why they are a better choice as a southern climate or greenhouse variety.

As garlic is a heavy feeder, be sure to keep your soil up to the demands of garlic. Using a slow-release organic fertilizer in your soil when planting your garlic is a good idea. Once the leaves begin to grow in spring, add a fertilizer blend that is high in nitrogen in the soil around your garlic plants.

Growing Garlic: Planting Garlic Bulbs

The soil should be nutrient-rich and well-draining. A slightly acidic to neutral soil pH between 6 and 7 is best for garlic. If planting garlic in outside beds around your dome, cover with a layer of mulch or untreated hay or straw for overwintering. We used dried corn husks and stalks after we harvested the corn cobs.

To plant your garlic, separate the bulb into cloves, leaving the thin, papery covering intact. Plant each clove 2-3” deep and 4-6” apart with the pointed end up. When planting garlic in a row, space them about 4” apart. 

When should you plant garlic? There are two options, fall or spring, and it depends on your climate. Most growers plant garlic in the fall for a summer harvest. If you heat your dome during the winter you may want to plant your garlic in early spring. Note: Seed garlic must be chilled prior to planting to break the cloves out of their dormant state. If you are planting garlic outside in northern climates, plant prior to the first frost. The soil temperature needs to have dropped to 60 degrees F. Mulch your garlic with 3-4” of straw mulch. If planting softneck garlic bulbs inside your dome, mulch is not necessary.

Garlic Care

Garlic needs full sunlight despite the fact that the most important part of the plant is underground. Plant your garlic where the plant will get 6-8 hours of sunlight per day.

Growing garlic requires nutrient-rich soil. It’s always wise to do a soil test. The soil pH should be between 6.0 to 7.0. Soil should drain well and be moist. If planting garlic outside in the summer it helps to cover them with mulch or hay to prevent weeds, retain moisture, and add an extra layer of warmth in cold climates. 

Garlic doesn’t require as much water as other crops. It prefers moist soil with about one inch of water per week, slightly more if the weather is very warm. It is important to allow the soil to dry for two to three weeks prior to harvesting. Soil that is too wet around harvest time can cause mold. It is best to harvest garlic before the hottest part of summer.

Temperature is key to growing garlic. The cold winter months are actually the best for growing garlic. If you live in a cold climate and are planting garlic outside your dome, plant your garlic about a month before the first hard frost.  

If you have soil concerns, consider using fertilizer when growing your garlic. One option is to mix a slow-release fertilizer in the fall when planting your garlic. Once the leaves appear in spring you can add a high nitrogen fertilizer blend around your plants.

Garlic Companion Plants

Companion plants are a bonus to any garden. Practicing companion planting will offer many benefits. They attract pollinators and beneficial insects as well as adding nutrition to the soil. They help retain moisture and offer weed control plus many of them have beautiful flowers.

Here are some of the best companions for garlic although it’s more about garlic being the companion: Beets, broccoli, cabbage, carrots, cauliflower, dill, eggplant, kale, kohlrabi, peppers, and potatoes. 

And once again, marigolds for the win! French Marigolds have a strong smell that helps repel nematodes. They also deter aphids while acting as a trap crop for other pests. Add these edible flowers to salad for a lovely garnish with a peppery taste. Other flowers that are garlic companions are geraniums, nasturtiums, and roses.

The following plants are not only good companions for garlic, but also improve your garlic’s growth: chamomile, rue, summer savory, and yarrow.

As wonderful as garlic is, there are some plants that will struggle if planted near garlic. When planted near garlic these plants will have stunted growth. Plant the following far away from garlic: asparagus, beans, parsley, peas, and sage.

Growing Garlic: Managing Pests

Garlic does have a some pests to watch out for. Plant parasitic soil nematodes are one of the pests that can damage garlic as well as other crops. They can live inside the garlic plant, eating and reproducing. Once in the soil, these pests can live and reproduce for years, sometimes without causing any damage for a season or more and then taking out an entire crop.

Inspect your plants frequently, and remove any diseased plants. Do not put diseased plants in your compost bin! Follow this link to learn more about beneficial nematodes and plant-parasitic soil nematodes.

Thrips

Another potential pest are onion thrips. Thrips damage the leaves of plants and suck up the seeping plant fluid. If the damage is severe the garlic plant wilts and then dies. You can use yellow sticky traps to catch thrips, but if you have beneficial insects in your dome the sticky traps will catch them also.

White Rot Fungus

In the middle of the growing season, white rot fungus can develop. This is one of the most serious diseases for garlic. Signs are leaves turning yellow, which causes them to wilt and die back. Infected plants will easily uproot as they are rotting. The best defense against this fungus is to get your cloves from certified disease-free stock. Once the field or garden beds have been infected with white rot fungus it can take many years before the infection is completely clear.

Growing Garlic: Harvest Time

If you planted a hardneck variety of garlic you get a preharvest bonus: garlic scapes! It’s best to harvest scapes while the stalk is tender and before the scape blooms. It also means your garlic plant will be able to help your garlic bulbs grow bigger once the scape is harvested. It’s a win-win!

Once your garlic leaves have turned brown around mid to late summer it is time to harvest. Carefully dig up a bulb or two to see if they are mature. Mature bulbs should be wrapped and not split.

The best way to dig up your bulbs is to use your hands, a garden fork, or a shovel. Dig straight down, but about 6” to 8” away from your plant. Then angle your hand or the fork to go under the bulb and gently lift it out of the ground. Do NOT pull the bulb out by the leaves as this might break the plant away from the bulb. Garlic can bruise easily so be careful and patient; it’s worth it.

Once you have removed your garlic from the garden, brush off the soil, but do not wash it. Cure (dry) the bulbs for about three to four weeks. A well-ventilated room or a dry, shady area outside will work. Once the tops and roots of the garlic are dry they can be cut off. Then clean the bulbs by removing the outer skin, but do not expose the cloves.

Store your garlic at low temperatures with moderate humidity. Room temperature is okay for storing garlic, but it will dehydrate more quickly. Store hardneck varieties for three to four months. Store softneck varieties for six to eight months.

Braiding Softneck Garlic

Softneck varieties will not produce scapes, but they are great for braiding. Try braiding your garlic this season! They also have a longer storage life and are milder in flavor when roasted.

After harvesting your softneck garlic, sort through your bulbs and set aside any bulbs with no tops. It’s best to use those immediately. Spread the remaining bulbs with tops in a dark cool area such as a basement for about two weeks. Try not to allow them to dry longer as the stalks may become too dry and brittle to braid. You will need 8-10 heads of intact softneck garlic and some twine or string. From here we suggest you click the link for full instructions on how to braid your softneck garlic. Or follow the braiding tutorial from Melissa K. Norris.

The History of Growing Garlic

Research shows that garlic has been cultivated for thousands of years. At least 4,000 years in Mesopotamia and thousands of years in Egypt and China. It is mentioned by the poet Virgil and by Pliny the Elder. Most amazing of all is that well-preserved garlic was found in Tutankhamun’s tomb!

Roman invaders introduced garlic to Europe in the Middle Ages. Although garlic was used medicinally, the ruling classes in Europe had an aversion to it because it was considered a “labor class” food. Hey, all the more garlic for the hard working. That changed during the Renaissance, 14th to 17th century, when Europe’s ruling classes became enamored with garlic in cooking. 

However, in China, ancient writings show garlic was used throughout the country as early as 2000 BC. The Chinese valued garlic for culinary purposes, food preservation, and its medicinal uses.

In North America a close relative of garlic has been growing for hundreds of years. Allium vineale (wild garlic, onion grass, crow garlic, or stag’s garlic) is a cousin of garlic (Allium sativum). Garlic as we know it arrived in North America in the 17th century via French, Portuguese and Spanish explorers. Thank you very much!

Garlic wasn’t cultivated much until immigrants from Germany, Italy, and Poland in the 1920s created the demand for this amazing plant. Now Gilroy, California (known as the Garlic Capital of the World) grows 90% of the US crop. China produces the most garlic overall.

Garlic Trivia

• Did you know that the city of Chicago derives its name from the native American word for the local, wild garlic plant “chicagoua”?
• Mark your calendars for April 19…National Garlic Day.
• Garlic, also known as Russian penicillin, was used to treat wounds during World War 2.
• Another use of garlic is to treat acne. Garlic has antiseptic and antioxidant properties. You can slice open a clove and rub it onto a pimple or apply garlic juice. Maybe not right before going out to a party or on a date, though.
• We don’t recommend storing your garlic in the medicine cabinet, but you can use it medicinally. Try it to remove splinters. Slice a thin piece of a garlic clove, place it on the splinter, apply a bandage, and leave it for a few hours. The garlic will draw the splinter out and the antibacterial properties will help prevent infection.
• Did you know that garlic was currency in the Middle Ages.
• The largest garlic bulb ever grown was in China in 2015 and weighed over 11 pounds.
• Garlic is a great remedy for aphid infestations. Crush garlic into water and spray it on plants and flowers. Bye-bye aphids.

Health Benefits of Garlic

We all know garlic keeps vampires away, at least according to fiction authors and Hollywood, but do you know what other benefits garlic has? Let us share with you.

Garlic is a good source of vitamins, minerals, and fiber. It provides us with vitamins B6 and C plus the minerals copper, iron, manganese, and selenium.

Garlic may help in boosting the immune system and protect against cancer. It is also thought to lower blood pressure (especially raw garlic) and cholesterol levels. Studies have shown that garlic can protect your liver from certain toxins and helps to lower blood sugar levels.

Raw garlic is of course more potent than cooked. Studies have shown that garlic is an anti-inflammatory, cancer-fighting crusader. The key compound in garlic, allyl sulfides, slows the growth rate of cancer cells.

If you LOVE garlic and your friends and family already know that, then try chewing and swallowing a raw garlic clove. This exposes bacteria to the healing properties of garlic and that fights off bacterial action inside the gut. Do you really love garlic? Plant hardneck varieties in the beds outside your dome and softneck garlic in your dome. You can look forward to enjoying garlic throughout the year in sauces, salsa, for medicinal uses and so much more.