Planting garlic in the fall, six weeks before the ground freezes, is the best way to ensure that the plants will begin to emerge in March or early April, according to Maurice Ogutu, U of I horticulturist.
He recommends a number of garlic varieties that perform well in Illinois. These include: hardneck types--Georgian Crystal, Music, Carpathian, Spanish Roja, Metechi, and Persian Star, and softneck types--Inchelium Red and Idaho Silverskin.
“There are several other varieties available and a home gardener can choose any of these as long as it is adapted to the local climate,” Ogutu said.
Garlic bulbs for planting need to be stored at temperatures between 40 and 50 degrees F.
“Most of the garlic bulbs in supermarkets are the softneck type and are not recommended for planting,” he said. “New garlic growers need to purchase bulbs from local garlic growers or through seed catalogues.”
Each garlic bulb is made up of several cloves held together by a thin membrane. Each clove consists of two miniature leaves and a vegetative bud. The bulbs should be separated into cloves when you are ready to plant. Only the larger outer cloves should be planted in order to ensure large bulb production.
“Garlic requires full sun, and deep well-drained, fertile soil with a pH of six to seven,” Ogutu said. “Garlic performs well in soil with plenty of organic matter so add plenty of compost, well-rotted manure, or till under green manure crops. Apply about three pounds of 10-10-10 fertilizer or the equivalent per 100 feet before planting.”
The cloves should be set up into the soil in an upright position (basal plate down) about two inches deep, spaced three to six inches apart within the rows. The rows should be 12 to 36 inches apart, depending upon the variety.
Planting time is critical as shoot and bulb development require cold treatment.
“Planting time is critical as shoot and bulb development require cold treatment,” he said. “Most of the leaf growth will occur when it is cool and day lengths are short. Leaf growth stops and bulb formation begins when it becomes warmer and day lengths are long.”
Ogutu recommends mulching the rows with four to six inches of weedseed-free straw mulch to moderate soil temperatures by minimizing fluctuations in winter and early spring, and to control the weeds.
“The mulch should be left in place throughout the entire growing season to control the weeds and conserve moisture,” he said. “However, in abnormally wet spring conditions, mulch may be removed after the danger of a hard freeze is gone so that the soil can warm up.”