By Susanne von Rosenberg, UC Master Gardener of Napa County
An easy way to spice up your vegetable garden is to plant onions and garlic. They are not difficult to grow. You can plant onions and leeks from now until January for harvest from May through July, depending on the variety. Plant garlic now through February.
Onions and garlic are in the allium family, along with leeks and shallots. Garlic and leeks take up very little room. You can grow them in containers or tuck them in among your flower beds.
Onions can be planted as seedlings from six-packs, as transplants (available at local nurseries now or soon) or as sets (baby onions). Sets are not recommended for California because the varieties are typically not adapted to our area and will bolt (form flowers rather than bulbs).
Planting at the wrong time will have the same result. Onions are cued to form bulbs by changes in day length. Intermediate-day onions and certain strains of long-day onions do best in our area; local nurseries have appropriate varieties. Short-day onions are not suitable for our area.
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; make sure you pick varieties that are suitable for our area.
Although small, onion and leek seedlings and transplants are hardy. As long as you provide fertile soil and adequate water, they will thrive. Keep them well watered and weeded initially, then keep the soil moist through the spring. Depending on our rainfall, this may require regular watering.
Plant onions four inches apart; they need room to form bulbs. Alternatively, 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.
To harvest leeks with long white sections, plant them at least four inches deep. Only the portion protected from sunlight will be white.
Onions are light feeders. Fertilize 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 leaves flopped over, I thought some critter had trampled my onions.
Garlic is planted as individual cloves. 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; there are hundreds of varieties of garlic from around the world, and they vary tremendously in pungency.
The two main categories of garlic are soft-neck and hard-neck. Soft-neck varieties (the kind you usually find at a supermarket) keep better than hard-neck types, but hard-neck varieties are easier to peel. Soft-neck varieties have multiple rows of cloves arranged around the center and average between 8 and 30 cloves per bulb. Hard-neck varieties have only one row, and average 4 to 12 larger cloves.
Grow soft-neck varieties if you want to braid your garlic. While hard-neck garlic supposedly needs more cold weather to form bulbs, I've always succeeded with it in my Napa garden. With soft-neck types you usually end up with a number of tiny cloves from the inner rows. I like to plant these in a container and harvest the leaves for green garlic in the spring. The leaves will be ready to enjoy long before your garlic bulbs have matured.
Hard-neck garlic plants send up scapes from their stalks. A scape is a thin green extension of the stalk that forms curls or twists and has a small bulbil, or swelling, near its end. Inside the bulbil are more than 100 tiny cloves that are genetically identical to the parent bulb. To focus growth on the garlic bulb you need to trim off the scapes. If you trim them before the tiny cloves form, you can use the scapes in recipes as you would green garlic.
Plant unpeeled garlic cloves, pointed end up, about one inch deep and four inches apart. Like onions, garlic plants like moist, fertile soil and 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, your garlic will be ready to harvest.
Garlic and onions must be dried if you plan to store them. Lift them from the ground with a garden fork after the soil has dried out completely. Lift the onions using a garden fork, then put them in a warm, dry place away from direct sun for a week or two. Garlic should be dry enough to store in two to three weeks. 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.
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I haven't always appreciated leeks. I grew up in a home where we never ate them, so I didn't encounter leeks until I was an adult. For many years I considered them kind of exotic and only cooked with them occasionally. Gradually I came to appreciate their unique flavor and sweetness and began to explore growing them in my garden.
Leeks are part of the onion family, which includes garlic and shallots as well as scallions (green onions) and familiar bulb onions. In flavor they resemble mild onions. In cooking, I've found that if a recipe calls for leeks but all I have are onions, I can still make the dish, and vice versa
When the Master Gardener field trial group decided to grow leeks last year, I enthusiastically joined in. I figured that growing them myself would provide a steady supply of fresh leeks all year.
The plan was to grow two kinds: an open-pollinated variety called ‘Lancelot' and a hybrid named ‘Megaton.' We hoped to learn whether one had any advantages over the other in flavor, size or vigor. I also hoped to learn more about growing them.
Leeks are considered a cool-season vegetable, and most sources recommend planting seeds or transplants in fall. Pam Peirce's book, Golden Gate Gardening, suggests early spring planting for a crop through summer and fall. This was the approach we decided to take.
Two of us agreed to start plants for the whole group. Seeds were started in nursery containers in January. Because leeks grow slowly and do not require much room, they can be sown relatively thickly. The seed packets said to sow seeds ½ inch deep and ½ inch apart. A four-inch pot handled 16 to 20 seeds easily with that spacing.
Seeds sprouted readily, in less than two weeks. After about eight weeks, around the middle of March, the seedlings were beginning to crowd the pot. They were sending roots out the bottom, indicating that it was time to transplant them into the ground.
Leeks prefer enriched soil so most of us added compost and fertilizer to our planting beds before setting the plants out. Spacing them at least six inches apart would allow the plants to develop to their mature size of one to two inches thick. They need regular water, and most gardeners used a drip line and watered a couple of times a week. Leeks have relatively shallow roots, so frequent watering is better than deep soaking.
Leeks take a long time to size up. While you can eat them at any stage, we were aiming for large leeks similar to the ones in the grocery store. With that standard, we harvested the first leeks around 90 days after transplanting, right on time according to the seed packet. That equates to harvesting in late June and July. Some of the gardeners continued to have a good-quality harvest into fall, with the leeks getting a bit larger with time.
Ten Master Gardeners reported results. As this is a small sample and we planted relatively few seedlings (10 to 20 of each variety), our findings are not statistically valid. Still, they are worth sharing. Fewer than half of the leeks we transplanted made it to maturity, mostly due to gophers or squirrels finding them irresistible. We found ‘Megaton' somewhat better than ‘Lancelot' in terms of size, but we disagreed on which variety was tastier.
Of the ten Master Gardeners who participated in the trial, more than half said they will grow leeks again. For me, having fresh leeks in the summer was convenient. Prior to this experiment, I had confined my leek planting to fall.
While I have enjoyed some success growing leeks over the winter, they never lasted past spring without bolting. Now that I know that leeks planted in early spring will do well through the summer, I intend to start leek seeds once or twice in late winter so I can enjoy these versatile onion relatives more often.
Workshop: U. C. Master Gardeners of Napa County will host a work on “Ten Things to Know about Fruit Trees” on Sunday, February 12, from 11 a.m. to 1 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Fruit trees want to produce fruit. Learn how home gardeners can nurture their fruit trees to be as productive and healthy as possible. Cost is $12 per person; free to Yountville residents. Register with Yountville Parks & Recreation or call 707-944-8712.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
The Napa County Master Gardeners' field testing committee is currently growing two varieties of leeks. One is ‘Lancelot'; the other is ‘Megaton'. I started mine from seed in late January. By planting different varieties, you can harvest leeks practically year round. Early types are ready to harvestfrom early to mid-fall. Mid-season varieties are ready from early to midwinter, and late-season varieties can be harvested in early to mid-spring.
Leeks are a winter-hardy crop with a mild onion flavor. Their edible shank, six to ten inches long, can reach two inches in diameter. For a winter crop, plant seeds directly in the garden in fall. You can also purchase nursery seedlings, which looklike pots of unmown grass. You will need to untangle these seedling clusters and plant them individually.
Plant seedlings as soon as the soil is dry enough to work. Dig a six-inch-deep trench and plant seedlings six inches apart. You can also poke holes with the handle of a rake or hoe and drop the seedlings into the holes. Watering will wash enough soil around them to cover the roots. The holes will fill with soil gradually as the plants grow, keeping the shanks pale. This process is known as blanching, and the more blanching the better.The blanched shank will be tender, while the strappy green leaves can be tough.
Leeks are slow growers, requiring 120 days or more to reach one inch in diameter. They prefer full sun; fertile, well-drained soil; and regular watering. Moisten the soil thoroughly once a week to a depth of 18 inches. Organic mulches help conserve water, supply nutrients and reduce weeding. After the leeks reach sufficient size, you can harvest outer leaves, but beware that harvesting too many may limit the growth of the shank.
Control weeds through regular cultivation, taking care to avoid damaging the shallow leek roots. Weed control is particularly important during the first two months. Onion maggots can destroy leek seedlings and will continue to feed as the bulb expands. To control them, consult the University of California Integrated Pest Management guidelines (http://www.ipm.ucdavis.edu/PMG/r584300211.html). For other common pests and diseases that may affect your leeks, read the university's pest-management tips for onion and garlic (http://www.ipm.ucdavis.edu/PMG/selectnewpest.onion-and-garlic.html).
To prepare leeks for eating, cut away the tough, thick greens. Reserve them for stock or toss them in the compost. Leeks can be frustrating to clean because soil is often lodged between the layers. If you intend to cook the leeks whole, slit them lengthwise, stopping about two inches short of the root end. Trim the root end but leave it intact. Wash well under running water, making sure to rinse between the layers.
If you are going to be slicing or dicing the leeks, first remove tough outer layers and trim away the roots. Slice or dice the leeks, then add them to a bowl of water, swishing well with your hands to dislodge any dirt. Lift the leeks out with a wire-mesh sieve or slotted spoon.
Leeks add a delicate onion flavor to soups and stews. Make a potato-leek soup or braise sliced leeks with peas.
Poach them whole, chill them and serve them with mustard vinaigrette. Or saute them and add to an omelet or frittata.
Leeks store well. Refrigerate in a plastic bag and use within a couple of weeks. They are low in calories and contain kaempferol, a phytochemical that may protect against some cancers.
Legend has it that, in 640 A.D., Welsh warriors led by King Cadwallader placed leeks in their hats during battle to distinguish themselves from Saxon enemies. References to leeks growing in Egypt can be found in the Bible. Ancient Egyptians held the leek in such high regard that swearing by this member of the onion family was the same as swearing by one of the gods.
Workshop: U. C. Master Gardeners of Napa County will lead a workshop on “Growing Tomatoes” on Sunday, April 10, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Topics include soil temperature requirements; types of tomatoes; care and fertilizing; support choices; and integrated pest management techniques for common tomato pests. Register at the Parks and Recreation Department at 707-944-8712 or on its web site.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site.
Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.