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 cooked with them only 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 1/2-inch deep and 1/2-inch apart. A 4-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 1 to 2 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 10 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: The Integrated Grape Team from the UC Master Gardeners of Napa County will host a workshop on “Home Vineyard 1” on Sunday, Feb. 5, from 12:30-4:30 p.m., at White Rock Vineyards, 1115 Loma Vista Drive, Napa. Learn what to do, what to look for and what to plan for in the vineyard between February and August. This is an outdoor lecture, so dress accordingly. Registration is $5 per person. Online registration (credit card only) Mail-in registration (check only or drop off cash payment).
Workshop: Master Gardeners of Napa County will host a work on “Ten Things to Know about Fruit Trees” on Sunday, Feb. 12, from 11 a.m. to 1 p.m., at the Yountville Community Center, 6516 Washington St., 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.