The best time to plant garlic is either in early spring or late fall/early winter. Garlic will be successful in most regions of the United States. There are some trade-offs based on which you choose.
Garlic planted in the spring often produces smaller bulbs if the weather is bad. In the South, where the weather is warmer, spring planted garlic does well. Planting in late February or March eliminates the chance your garlic will be damaged by winter temperatures.
If you plant in the autumn, you will have larger bulbs but you will also need to mulch your garlic bed heavily with leaves, grass hay, or alfalfa to protect it from freezing temperatures if your snowfall is slight. Do not use straw as it harbors wheat curl mites that can attach your garlic.
Plant your garlic before the first major freeze, preferably at least a month before so that the bulbs have time to root and just begin to sprout before the cold weather sets in. In cold climates, plant no more than three weeks before the first frost date.
Garlic is grown from the cloves that are taken from the larger garlic bulbs. If you are planning to plant the garlic, remove the cloves just before planting. Although you can plant the bulbs you get at the grocery store, you’ll have better luck with bulbs bought from a nursery. Some grocery varieties are sprayed to prevent sprouting. Choose bulbs with large cloves, as this is an important determinant of the grown bulb size.
Plant your garlic in loose loamy soils, high in organic matter such as compost or well-rotted manure. Add 10-10-10 fertilizer or blood meal to the planting bed. Break the larger cloves off the bulb, and make sure part of the woody basal plate comes with it. This is where the new roots will form. Save the smaller cloves to eat, pickle, dry, or to plant together in the spring for early eating, much like green onions. The smaller bulbs will not perform well if planted for new bulbs.
Set cloves in the ground about four to eight inches apart. Plant them with the pointed part of the clove up, about two inches deep. Especially in the fall or winter, it’s a good idea to cover with a layer of mulch. However, mulch in wet climates can cause your garlic to become waterlogged. To prevent heaving from repeated freezing and thawing, use a thick layer of mulch, at least four inches or more.
Water your garlic so that it stays moist during the growing season. Mulch will help retain moisture. If your garlic fails to produce full-sized bulbs, you may not be providing enough water. On the other hand, overwatering can lead to burst skins and mold. If you plant garlic to over-winter, it’s best to stop watering too soon that too late. A few weeks before harvesting, stop watering. Harvest when the leaves of the plant die back.