MSU Extension Vegetables

Successful production of any crop starts with proper seed, planting time and soil conditions – garlic is no exception. The “seed” of garlic is the individual clove and the manner and time in which it is planted is similar to other bulbs like tulips and daffodils.

It is important to understand the two types of garlic – softneck and hardneck. Softnecks do not produce a “scape,” which is the structure giving rise to the “flower” (Photo 1). Garlic does not flower but produces bulbils where the flower would form. Bulbils are clones of the parent and can be used as planting stock, but may take two years to produce a marketable product. Hardneck scapes are usually removed, resulting in larger bulbs. Softneck types are generally grown in milder climates than Michigan since they are less cold tolerant. Softneck garlic also has cloves arranged in layers that get smaller toward the center of the bulb. Hardneck garlic cloves are arranged like pieces of a pie with the scape at the center and cloves are more uniform in size. Overall yields are less with hardnecks, but this is offset somewhat by having more useable cloves since many small, softneck cloves are left unused since they are difficult to peel for the amount of garlic obtained. Two hardneck varieties that have done well under Michigan conditions are German White and Music. However, there are many other varieties worth trying. Check out the Garlic Seed Foundation website for possible seed sources. The increase is about six times what you plant – one pound of seed garlic will produce 6 pounds of marketable cloves.

Seed garlic is difficult to obtain this time of year. So unless you have made prior arrangements, you will have to start planning for your 2012 planting. Many first time growers think they can use garlic purchased from the grocery store, but this usually results in disappointment. Garlic for consumption is generally stored just above freezing, while garlic for planting is stored around 50°F. The lower storage temperature changes the physiology of the plant such that it tends to produce multiple, smaller bulbs rather than one large bulb.

To prepare garlic for planting, simply break the bulbs into individual cloves. This is done by hand for smaller plantings or mechanically for larger plantings. Look for any signs of disease and discard suspect cloves. There is a direct correlation between size of the seed clove and size of the bulb it will produce. Smaller cloves can be sorted out and planted closer together for harvest as green garlic. Green garlic is harvested before the plants bulb, giving a product similar to green onions.

Garlic does best in a well-drained sandy loam soil with a pH of 6.5 to 7.0. It does not like clay soils since the compactness can hinder bulb growth. It does well in organic soils, but the color tends to stain the skin and reduce quality.

Reddish soils can also stain skins. Work the soil 8 to 10 inches deep and incorporate 20 to 25 pounds per acre nitrogen. Any phosphorous and potassium recommended by a soil test should also be applied at this time.

Actual planting patterns vary depending somewhat on equipment. They can be planted in single, double or triple rows or in a bed with the between row and bed spacing depending on the width between your tractor tires. In-row spacing for high quality garlic is usually at 4 inches between plants, regardless of the row arrangement. A 4-inch deep trench is made and each clove is hand-planted with the basal plate pointing down and the trench then covered (Photo 2).

Garlic should be planted six weeks ahead of the ground freezing. This is usually sometime in October depending on where you live in Michigan. The goal in the fall is to only have the bulbs produce roots and no shoots above the ground. If shoots emerge, you planted it too early, too shallow, or it is a variety that is not well-adapted to your area. To give added winter protection, some producers will put a layer of straw mulch over the planting. This is possible for small plantings, but may not be economical for larger ones.

More information on garlic can be found in “Producing Garlic in Michigan,” Michigan State University (MSU) Extension Bulletin E-2722, available at your local MSU Extension office or on the Vegetables webpage. There is more to discuss on garlic production, but I will save that until next spring.