Learn how to start garlic, different garlic types including when to harvest hardneck garlic, and details about garlic growth time through each season.
If I could grow only one crop, it would be garlic: pungent, mouthwatering, plump-cloved, health-promoting garlic. Over the years, I have learned some tricks on how to grow garlic that’s truly exceptional. Before you dig in, you need to know the basic types to choose from.
Garlic Types
Garlic (Allium sativum) is divided into two subspecies: var. ophioscorodon and var. sativum. Most often planted in climates with cold winters, ophioscorodon garlic is called “top-setting,” “ophio” or “hardneck” garlic; the family includes Rocambole, Continental and Asiatic types. Leaves grow from a hard, central stalk, and then an edible scape (flower head) forms, with tiny buds called “bulbils.” Most hardneck varieties form four to eight cloves around the central stalk’s base. Their flavor tends to be pungent, but often has subtle notes.
The sativum varieties do well in all climates. Called “softneck” or “artichoke” garlic, heads tend to be large, with 12 to 20 small cloves and no central stalk. Leaves, which sprout directly from each clove, are quite flexible and best for braiding. Generally, softneck garlic can be either pungent or mild, but lacks subtlety.
Garlic Growth Time and To-Dos by Season
How to Start Garlic This Fall
For the biggest heads, always plant individual garlic cloves in fall. Each clove will form a new bulb by the next summer. Garlic thrives on spring and summer sun and moderately cool nights — it needs heat to form its bulb. Choose a site with deep soil rich in organic matter. Soil that has been built up with cover crops the previous year is ideal.
Before planting, add 1 to 2 inches of compost or well-rotted manure to a deeply cultivated plot. Garlic requires nitrogen to nourish fall root growth. I add nitrogen in the form of fish meal or alfalfa meal at a quarter- to a half-pound per 10-foot row. Organic soybean meal supplies slow-release nitrogen that lasts in the soil until bulb production takes place the next spring. Apply a half-pound per 10-foot row. (You can buy soybean meal, alfalfa meal and kelp meal at farm and feed stores.) The organic soil additive Azomite, a type of rock dust, has significantly increased the yield and size of my garlic crop. I add a half-pound per 10-foot row. If you can’t find Azomite, kelp meal applied at the same rate can supply extra minerals.
Start with certified disease- and pest-free garlic from a reputable supplier. Make sure it has been tested to be free of garlic bloat nematode. If you plant infected cloves, the nematodes will colonize your soil. They kill garlic before the bulbs mature. Seed cloves are also vulnerable to Penicillium decay, a disease that appears as a bluish-green mass. Garlic may be susceptible to basal rot, white rot or botrytis rot (which is sometimes called “neck rot”). Basal rot may cause yellowing and dieback of leaves, and may manifest as a white fungal growth at the bulb’s base. White rot causes fungal growth on the stem that extends around the bulb’s base, and afflicted bulbs will have a blackened neck with water-soaked outer scales. Botrytis rot causes water-soaked stems and gray, fuzzy fungal growth. Little can be done to control these diseases; you’ll need to pull affected plants.
Plant garlic four to six weeks before your ground freezes in fall. If your ground never freezes, plant a month before the coolest time of the year. Timing will determine the number of cloves in your garlic bulb. If you plant early, the garlic will set its roots into warmer soil and deduce that it has lots of nutrients available, and thus make plans to form more cloves. If you plant later, the garlic will perceive less nutrient availability and set fewer cloves. Both heads may grow to be the same size, but the later planting will have fewer, larger cloves.
To grow large heads, devote more planting space, as the roots of a well-developed garlic bulb can spread out 6 inches. Space garlic 10 inches apart in rows at least 1 foot apart. Plant individual cloves 2 to 3 inches deep, pointed end up. Garlic thrives on even, not-too-heavy moisture and prefers cool roots, so irrigate as needed and mulch deeply with straw, shredded leaves or hay. Mulch will also protect against frost heaving and smother weeds, which is important — garlic despises weed competition. Free up any spears that can’t pierce the deep mulch in spring.
Spring: Cultivating the Garlic
In spring, I foliar-feed fish emulsion (1 tablespoon per gallon) every two weeks until scapes appear, or side-dress with blood meal (2 to 3 teaspoons per head) four to five weeks into the season.
Hardneck varieties will send up a scape a few weeks before harvest. Clip these stalks after they have emerged, before they curl. This will force the plant to put its energy into the bulb rather than scape formation. Don’t just toss the garlic scapes — find delicious ways to cook them by reading Garlic Scapes.
Summer: When to Harvest Hardneck Garlic
Wait until a relatively dry period, if possible, for optimal harvesting and curing. Dig garlic when the plant’s bottom leaves have yellowed. As the leaves die, layers of the papery “wrapper” around the bulbs will begin to decay, so harvest before you lose too many.
To harvest, loosen soil with a fork, pull the bulbs from the ground and shake off the soil. Garlic bruises easily, so avoid banging the heads. The crop is also vulnerable to sunscald, so remove the heads to a shady spot.
Next, trim the tops and roots, and arrange the bulbs on racks to dry and cure. Or, leave the plants intact and hang in small bunches or spread on racks. I use room fans to dry my garlic crop quickly. After garlic is fully dry (in about three weeks), remove all remaining roots and gently brush off any lingering soil. Store garlic in mesh bags in a cool, dry, dark place. Storage longevity will depend on the variety, but will range from six to 12 months.
To save planting stock from your summer harvest, choose 2 to 2-1/2-inch bulbs that have the variety’s best characteristics. Set aside the plumpest, largest cloves from within those bulbs to plant again in fall. Avoid double and sliver-like cloves, as the doubles will create a double bulb with a flat side, and the slivers will usually form a small bulb.
For more on how to grow garlic and other fall crops, see How Does Garlic Grow?
Roberta Bailey has grown garlic for decades on her 18-acre farm in Maine, which is surely a vampire-free zone by now.
