Garlic is planted in the fall, after the first light frost but before the ground freezes, usually in late October or November. Overwintering (exposure to cold) is essential for bulb development. Garlic is a heavy feeder, so plant in fertile, well-drained soil rich in organic matter and nutrients. Keep bulbs intact until you are ready to plant them, then break up into individual cloves leaving clove skins intact. Plant cloves about 2" deep into the soil, 6-8" apart in rows spaced 12" apart. The tapered end of the clove should point up, and the flatter end with the attachment point should point down. Covering the soil with a layer of mulch (straw, oak leaves) helps suppress weeds, retain moisture, and fertilizes the soil. Do not remove the mulch in the spring. Keep well weeded for best results as garlic does not compete well against weeds. Garlic will benefit from regular watering (at least 30 minutes 2x per week).
Hardneck garlic will produce scapes which are edible flowering stems that develop in early summer. Break off the scapes and use as a vegetable. Harvest the bulbs when the lower 4-6 leaves of the garlic plants are yellow/brown (sometime in July), loosen the soil with a digging fork and carefully lift the bulb out of the soil. Brush off the dirt, then hang garlic or lay out on raised screens in well ventilated area away from sunlight, to cure for about 10-14 days. After curing, trim roots off and cut stem to about 1" above bulb. Outer skin should be crispy dry, and cut stem should be hard. Garlic is best stored at 50-70°F and around 50% humidity.
Save the biggest bulbs for planting stock for next season. Keep bulbs cool and dark until ready to plant (but not in the fridge because this can make it sprout.) If scapes are not removed during growing, the scapes will form bulbils, which can be collected and planted like seeds. During the first growing season, planted bulbils will grow into single cloves, which can be dug up and re-planted to produce full bulbs the following year. In rare cases, scapes can produce "true" seed, which does not grow true to type.