Raising a stink

Known for its pungent odor, robust flavor and mythical vampire-repelling power, garlic has long been an essential kitchen staple for home cooks and professional chefs alike. In recent years, however, the popularity of this aromatic allium has soared, especially among Americans. Garlic consumption has quadrupled in the U.S. since 1980, with each person now eating more than 2 pounds per year, according to USDA. 

However, most of that garlic was grown elsewhere, likely China, which produces 80% of the global supply. Not only is the U.S. the world’s largest garlic consumer, it is also the world’s largest garlic importer, purchasing about 340 million pounds annually. That’s about half of domestic demand. In the U.S., about 400 million pounds of garlic is produced, mainly in California with Oregon, Nevada, Washington and New York following in the distance. 

Horticulture specialists at the University of Missouri Extension would like to see more of that production move into the Midwest.

“Garlic is a specialty crop that Missouri is well-suited for growing,” said Patrick Byers, MU horticulture field specialist in Webster County. “Farmers can produce a significant amount of garlic on a small plot of land with good profit potential.”

In May, Byers helped organize and host the first-ever Missouri Garlic School to foster interest in growing this specialty crop on a commercial scale. The day-long event in Springfield, Mo., included classroom presentations from national and regional experts and tours of local produce farms where garlic is grown. More than 75 people attended, such as Micah Kuenzle, who operates FirstFruits Valley Farms near Ozark, Mo. The young farmer is considering growing garlic behind his pumpkin crop. 

“This conference has been very helpful because garlic is new for me,” Kuenzle said. “The acreage I’m farming is small, so I’m always looking for ways to make it more productive.”

Planted in the fall for summer harvest, garlic is a cool-season crop in the same family as onions, chives, shallots and leeks. There are two main types of garlic, hard-neck and soft-neck, as well as elephant garlic, which is more closely related to a leek. Most garlic found at the supermarket is soft-neck because it is easier to grow and keeps longer than hard-neck varieties. Hard-neck varieties, on the other hand, can withstand colder temperatures and are the only ones that produce scapes, the flavorful serpentine stems that grow from the bulb. The scapes are typically harvested in early summer to allow the garlic plant to channel all its energy into the bulb. They’re a value-added product for farmers and seasonal favorite among consumers.

All these types of garlic can be successfully grown in this region, said Rusty Lee, Extension agronomy field specialist in Montgomery County, who spoke at the Garlic School. In addition to researching its production, Lee grows garlic commercially at his family farm in Truxton, Mo. 

“Missouri produces about half the yields per acre as California, but our soil and climate still produce good yields,” he said. “Garlic needs a cold winter, wet spring and dry summer. We’re in a good growing area.”

Garlic not only grows well in the Midwest, but it also sells well, said Dan Bigbee, owner of Fassnight Creek Farm, one of the tour stops for the Garlic School students. He recently added garlic to his diverse selection, which includes vegetables, flowers and ornamental plants. He operates on about 30 acres surrounded by subdivisions and development in the heart of Springfield and sells to consumers directly from his on-farm store. 

“I got interested in garlic last year after seeing it bring retail price or higher at wholesale auctions,” Bigbee said. “When you see that in any kind of agricultural market, your ears perk up. It’s just like having a homegrown tomato. People are willing to pay more for locally grown garlic than grocery store garlic.”

Fellow Springfield farmer Curtis Millsap also has found that garlic is a popular product among his community supported agriculture, farmers market and restaurant customers. The organic producer now raises five different varieties of garlic among the fruits and vegetables on his family’s Millsap Farms, the final stop on the Garlic School tour. He admits, however, that it took trial and error to learn how to grow the crop successfully.

“We’ve been here for 12 years and planted garlic the first year. We lost the crop every year for five years,” said Millsap. “Weed pressure was our biggest problem, and I was about ready to quit. We starting using biodegradable plastic mulch, and that was the game changer.”

Indeed, weeds can be garlic’s No. 1 enemy, said Crystal Stewart of Cornell Cooperative Extension, the featured speaker for the May conference. Stewart works with diversified vegetable farmers throughout a 17-county region in eastern New York. Her presentations covered pest management and post-harvest handling.

“If you really want your garlic to be amazing, you want to create a great growing environment—and that starts with weed control,” Stewart said. “Weeds compete with garlic for nutrients and create a moist environment, which makes it easier for diseases to develop.”

Pinpointing exact recommendations for growing garlic is difficult, Stewart said, because conditions vary from farm to farm and region to region. But she and the MU experts shared general tips with the Garlic School attendees based on research results and firsthand experience.

“What I might recommend to one grower is different from another,” Stewart said. “Use your horticulture skills and listen to what the garlic is telling you. If you do that, you’ll find the right garlic and have good results.”

Selecting varieties

Garlic is grown from cloves, the individual pieces of the garlic bulb. Don’t buy garlic from the supermarket to plant. Those bulbs have often been treated with growth inhibitors for a longer shelf life. Use certified seed garlic or cloves saved from garlic that was grown locally and is adapted to the native climate. Many growers save their own seedstock to plant, Lee said.“

Plant the best, and eat the rest,” he said. “Just by selecting the larger cloves to plant, it made a dramatic difference in the size and quality of the garlic we grew.”

Planting

Generally, garlic can be planted in the Midwest from late September until early November, before the first hard frost. This allows roots to develop but limits growth of shoots. Garlic will begin to sprout when the ground starts to warm up in early spring. Garlic grows best in a sunny location in soil that is well drained yet moisture-retentive and relatively high in organic matter. Separate individual cloves from the bulb, leaving the papery skin covering the clove intact. Select the large, outer cloves with the biggest heads. Plant in rows about 6 inches apart with cloves placed about 6 inches apart as well. Put the root end down (pointy end up) in a hole or furrow about 1 inch deep. Cover loosely with topsoil. 

Controlling weeds & pests

Only a limited number of herbicides are registered for use on garlic, so starting with a weed-free planting bed is essential. A non-selective herbicide such as glyphosate can be used as a burndown to help control perennial weeds. Thoroughly tilling the planting site is also an option. Either plant the cloves into a layer of plastic mulch or cover beds with loose mulch such as straw after planting to inhibit weeds, protect the soil from extreme cold and conserve moisture. “

Think about reducing weed pressure the year before planting garlic in that spot,” Stewart said. “What I like to do is intensively cover crop, depending on what weed problems I have. Crop rotation can also help. For example, if you follow a legume crop with garlic, then you’ve also helped grow your own fertility.”

Garlic is considered to be relatively pest-free, but it is prone to several diseases such as botrytis, fusarium (basal or bulb rot) and white rot (sclerotinia). Insects that can become a problem include thrips (especially during dry weather), onion maggots and wireworms. It’s important to plant healthy seed and work in clean fields. Crop rotation and moisture management can also help alleviate many pest problems.

Fertilizing

Garlic has moderate-to-high fertility requirements, especially for nitrogen. Conduct a soil test and apply recommended amounts of phosphorus, potassium, and lime before planting. A general rule of thumb is to use 3 pounds of a balanced fertilizer such as 10-10-10 per 100 square feet. Supplemental nitrogen should also be applied as soon as the leaves emerge in the spring and again about two weeks later. Avoid late applications of nitrogen, which can delay bulb formation.

“Optimizing fertility is a key to success,” Stewart said. “If everything else is right and your garlic still isn’t happy, look at your fertility.”

Watering

As is the case with most vegetables, garlic benefits from adequate amounts of water. If rainfall is not sufficient, use supplemental irrigation through drip lines or other sources. However, avoid applying too much water since excess moisture can result in bulb rot. Do not irrigate garlic once the leaves begin to mature and dry.

Harvesting

In the Midwest, garlic is usually ready to harvest between the second week of July and the first week of August. The garlic leaves will start to yellow and die back as the garlic matures. Stewart suggests harvesting and cutting open a sampling of garlic bulbs to determine if they are ready.

“Cloves grow from the inside out, so it should push as far against the skin as possible without breaking it,” she explained.

To harvest, dig or undercut the bulb with its roots and leaves attached. Leaves can be trimmed before curing if you prefer. 

“In our research, we showed no statistically significant differences in trimmed versus untrimmed garlic in terms of bulb quality, weight or disease incidence,” Stewart said. “So really, it’s your preference whether you want to leave the tops on or not.”

Remove excess soil or mud, but avoid washing newly harvested bulbs. Much like paper yellows after it gets wet, Stewart said she found that washing can discolor the bulb’s outer wrappers.

Curing and storing

There are many different methods of curing and storing garlic, the Extension experts said, but in general the harvested bulbs need to be in a dry environment with good air circulation for three to four weeks. Either tie bulbs together and hang them to cure or spread in a single layer on drying racks. 

“How do you know if it’s dry?” Stewart asked. “The way I tell is to take five or six bulbs and then peel back to the inner leaf. If the innermost leaf is dry, you know everything is dried. As soon as it’s dried, get it into your storage environment, because it will keep losing moisture. Over-drying garlic is a big problem.”

After curing, the bulbs will be ready for storage in a cool, dark place such as a basement or heated garage. Store garlic below 75° and below 75% relative humidity. Expected storage life depends on type. Hard-neck types will store for three or four months whereas soft-neck types can be stored for six to eight months. To keep fresh bulbs longer, immediately place harvested garlic in cold storage—around 32° and 70% relative humidity. Keep in mind, however, when cold-stored garlic is brought to warmer temperatures, it will soon start sprouting.

“You have to know when to harvest and how to store it properly,” Stewart said. “It’s disheartening to produce awesome garlic only to find out it rotted after harvest.”For more information, visit online at extension.missouri.edu. The MU Garlic School is slated to return in the spring of 2020. Watch for details at extension.missouri.edu/greene.