November 09, 2012 • By SUSANNE von ROSENBERG UC Master Gardener Napa County
Do you love onions and garlic? They're easier to grow than you might think, and now is the time to plant them.
Onions and garlic are in the allium family, along with leeks and shallots. You can plant onions from now until January for harvest from May through July, depending on the variety.
Onions can be planted as seedlings from six-packs, transplants (available at local nurseries now or soon), or sets (baby onions). Sets are not recommended for California because the varieties are typically not adapted to our area, and they will bolt rather than form bulbs. Planting at the wrong time will have the same result.
Sweet onions are ideal for eating raw. American onions are better for cooking and will keep longer. Yellow onions typically store better than white strains of the same type, and red onions fall somewhere in the middle.
Leeks are also easily planted as seedlings. You can start onions and leeks from seed as well; consult Napa County Master Gardeners for information on the best time to start seeds, as timing depends on the variety.
Onions need a minimum number of daylight hours to start to form bulbs. Intermediate-day onions and certain strains of long-day onions do best in our area; local nurseries will carry appropriate varieties.
Onion and leek seedlings and transplants are hardy. You may not believe that these tiny plants will survive transplanting, but as long as you provide well-amended soil and adequate water, they will thrive. Keep them well watered and weeded initially, then maintain a regular watering schedule through the spring.
Onions do not need a lot of fertilizer. Feed lightly before planting and again in early spring. When the leaves become less firm, the bulb is mature, and you can taper off the water. The bulb is fully mature when the leaves fall over. (They will still be green.) The first time I saw these prostrate leaves, I thought some animal had trampled my onions.
Plant onions four inches apart; they need room to form bulbs. Alternatively, you can plant your seedlings or transplants closer together and thin them for use as green onions or spring (immature) onions. They are edible at all stages of growth.
Plant garlic now through February. Garlic is planted in the form of cloves. Be sure to buy certified disease-free seed stock from a nursery, catalog or certified grower to avoid spreading disease in your garden. Consider trying an unfamiliar variety. At the Heirloom Festival in Santa Rosa in September, one grower had more than 100 varieties of garlic on display. Soft-neck varieties keep better than hard-neck types, but hard neck varieties.are easier to peel. Grow soft-neck varieties if you want to braid your garlic.
Plant individual unpeeled garlic cloves, pointed end up, about one inch deep and four inches apart. Keep the soil moist but not soggy. Like onions, garlic plants are light feeders. In May or June the leaves will begin to turn yellow, even with adequate watering. Taper off the watering, and when the leaves are at least 60 percent brown, the garlic will be ready to harvest.
Plant the smallest cloves from your seed garlic closer together and harvest the leaves for green garlic. These leaves have a mild garlic flavor and will be ready long before your garlic bulbs have matured.
Garlic and onions must be dried if you plan to store them. Lift them from the ground with a garden fork. Wait until onions are completely dry in the ground before lifting them, then put them in a warm, dry place away from direct sun for a week or two. Garlic will take two to three weeks to dry enough to store. After your onions and garlic are sufficiently dry, bush off the dirt, trim the roots to one inch, and either braid the tops or cut off the tops about two inches above the bulb.
Napa County Master Gardeners (cenapa.ucdavis.edu) answer gardening questions Monday, Wednesday and Friday, 9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221.