Onion chives and garlic chives are very similar in the way they are grown as well as cooking use. Chives are the easiest herb to grow, requiring virtually no attention.
Sun Requirements: 6 to 8 hours sun, will be fine in all day sun
Soil: Chives prefer an organically rich well drained soil with a pH of 6.0 to 7.0.
Moisture: Thoroughly moisten soil regularly to support frequent harvest.
Spacing: 8 to 12 inches apart
Feeding: Mix organic nutrients or slow release granular fertilizer into the planting soil. Apply a balanced 20-20-20 liquid fertilizer every 3 to 4 weeks to support frequent harvesting.
Growing from Seed: Sow seeds after the last frost, ideally after soil reaches 60 degrees, and thin 3 inch seedlings to about 8 inches apart. The first growing season will not likely produce a large enough clump for much of a harvest.
Problems: May occasionally be bothered by aphids or thrips as well as rust and fungal diseases. Typically chives are quite resistant to problems. Cut the stems with flower buds to the ground to minimize reseeding. Chives spread readily but not aggressively.
Chive clumps are pretty hardy perennials able to survive very harsh conditions. When grown in poor soil, dry conditions, heat or wind, they will continue to grow and spread but not as rapidly as in ideal conditions. Pinch off flower buds, or cut the entire stem to the ground, to encourage faster leaf production. If you allow your chives to flower, the flowers are also edible and should be used before they dry and disburse seeds. After a hard freeze cut the plants back to soil level. Every few years dig up the clumps in spring and divide.
Garlic chives can be harvested when quite young. By the time they reach about 6 inches high you can begin harvesting from the outer stems of the clump. Using a garden or kitchen shears simply cut just above the soil surface. New growth will continue to spread out around the outer edges.
Store chive leaves in a tightly sealed container in a cool place.
Chop up leaves and freeze to be tossed in soups or sauces. Or freeze in ice cube trays with oil or butter to be tossed into a sautee pan or tossed with pasta. Chive leaves do not dry well as they dramatically lose flavor.