Garlic is a bulb of the lily family but also related to the chive and onion family. Garlic bulbs should be planted in November or December. Right before planting, divide the bulbs into cloves. Use the largest outer cloves of each bulb for your seed stock. These cloves will produce better quality plants.
Garlic prefers rich, loose, fertile soil. A heavy soil will restrict bulb growth. Do not plant garlic where onions have been previously planted. The soil may be contaminated with common diseases or pests. Planting the clove with the root system down is not necessary, as the clove planted will disintegrate as the plant develops. Plant the garlic in full sunlight and in moist, but not soggy, soil. Plant the cloves 2 inches deep and 4 inches apart. Distance between rows should be 12 inches to 18 inches.
Garlic requires twice as much fertilizer as most vegetables. Under normal conditions, you should water deeply to a depth of 24 inches. Discontinue irrigation as soon as the plant tops naturally fall over and become dry. Let the soil dry for a week or two before harvesting.
When harvesting the garlic, lift the bulb carefully using a spade to loosen the bulb from the soil. Do not bruise the bulb. Store the garlic in a shady, well-ventilated place to dry. You can tie small bunches together on a wire or rope. Keep the bunches to a group of 10 or less for air circulation as thy hang to dry. Dry the bunches for 2 or 3 weeks. After drying, cut the stalks to 1" above the bulb. Trim off the root system. Store the bulbs in a cool, well-ventilated place.
Some expert gardeners plant garlic on the shortest day of the year and harvest on the longest day of the year. If you plant in December in Gilroy, your garlic should be ready to harvest in late June or July.
Garlic and onions interplanted with roses, cause the roses to produce a stronger perfume in larger quantities. This is practiced in Bulgaria, where attar of roses is produced for perfumes.