CORVALLIS, Ore. – In mild parts of western Oregon and along most of the coast, it is possible to grow a succession of garden vegetables throughout the year. You can extend the season well into fall in many parts of the Pacific Northwest with a little knowledge and protection of your plants from the elements.
When space becomes available after harvesting the last of your spring-planted peas or greens, keep those veggies coming.
Even though your summer vegetables are growing like mad, late June through the first of August is time to plant many of your fall garden seeds in many parts of the Pacific Northwest. Lettuce and winter greens can be put in until August in many locations. Transplants can be put into the ground up until the end of July for best odds of a fall and winter harvest.
When planning a winter garden, choose the warmest, most sheltered spots in the garden, advises Ross Penhallegon, Oregon State University Extension horticulturist. Choose heat-resistant varieties and shade and water them frequently as they grow. Enation-resistant pea varieties include Oregon Pioneer shelling peas, Sugar Daddy snap peas and Oregon Sugar Pod II snow peas. Bolt-resistant greens include Tyee spinach and oak leaf lettuce. Greens can be planted in the shade of taller plants for summer and fall growth. July is a good time to put in more carrots for fall and winter harvest, as well.
"Be sure you avoid poorly-drained or windy sites and places that are frost pockets," said Penhallegon. "And add a good dose of organic matter to clay soils prior to planting for fall and winter."
Keep carrot seeds moist until germination. In hot, dry weather, a damp burlap sack or light mulch over the row will ease germination. Keep it damp and check for germination every five days. Twenty to 30 feet of row should keep a family of four in carrots into spring. Royal Chantenay, Danvers 1/2 Long and Merida are good carrots for planting in July and can be harvested all winter.
Other vegetable varieties that will grow through the winter include purple-sprouting broccoli, Utah-improved celery or President endive. Many kinds of Swiss chard, even if planted in the spring, will overwinter and resprout the following spring. Improved kales are a very reliable crop to plant in late June into July.
Most members of the cabbage family can be harvested in fall or early winter if planted by early July. Many other greens in this group, such as Chinese cabbage, kale, collards and mustard, hold well into the winter.
If you missed planting leeks in May, try garlic or overwintering WallaWalla sweet onions. Both can be planted in September, and harvested the following late spring into early summer.
Slugs can be a major problem in the fall and winter vegetable gardens. Use properly labeled slug baits until cold weather arrives. Many gardeners prefer the least toxic iron phosphate baits such as "Sluggo," for environmental and safety reasons. Another way to reduce slugs is to thoroughly till the soil before planting to reduce the slug population. Tender crops such as buttercrunch or black-seeded Simpson lettuce especially need protection from both slugs and rain. For best results, grow them under cloches or cold frames during the late fall and winter.
The OSU Extension Service offers a guide to winter gardening for all areas of the Pacific Northwest, called "Fall and Winter Gardening in the Pacific Northwest," (PNW 548). It includes variety recommendations and temperature limitations for each vegetable. Season extending techniques are provided as well. View it online or purchase a printed copy by calling 1-800-561-6719.