The Northwest's seasonal rains and generally mild falls and winters make it easy to enjoy fresh, homegrown veggies even after first frost. Plus, cooler temperatures bring fewer insect pests, so growing organically is a snap.
The work for winter crops like leafy greens, cauliflower, turnips and broccoli starts in early to mid-summer. That's when you'll need to prepare a patch of soil and sow seeds or plant transplants. You can plant some crops, like garlic, in early fall. Here are the basics to get you started:
Choose a site
Pick a location in your yard that gets as much sun exposure as possible on short winter days (like along a south-facing wall). Avoid spots that will be buffeted by cold east winds. Frost comes earlier to the bottoms of slopes, so higher is better to maximize frost-free growing days.
Prepare the soil
Rains will saturate the soil, so make sure it will drain well, or plants will be vulnerable to root rot. For maximum drainage, consider building a raised bed.
Add compost; it not only improves drainage, it adds nutrients back. Also mix in organic fertilizer – even if you amended the soil in spring, summer crops will have depleted its nutrients.
Then spread a 3-inch blanket of leaves, compost or shredded bark on top. This and other types of organic mulch protect the soil and add a food source for bacteria, fungi, insects and other invertebrates that add nutrients your plants can use. Plus, organic mulch is like a year-round farmer's market for robins and other pest-eating wildlife.
In August and September, patrol the mulch for slugs and snails; remove them manually and you'll have fewer pests in the spring.
Choose what you'll grow
Because of our relatively late first-frost date (around Thanksgiving), you can grow warm-season crops like beans or squash into mid-fall, as long as you allow enough days to harvest before frost.
You can harvest cool-season crops throughout the winter. Kale, turnips, arugula, greens and broccoli are some. Many do fine uncovered after a mild frost (30 to 32 degrees) and with protection during extremely cold weather. Some, like parsnips and Brussels sprouts, taste even better after they're frost-kissed.
Fall is a great time to plant shrubs, and even winter-planting of cold-hardy plants can give them a head start before the summer heat.
Plant from early to mid-summer
Plant in early to mid-summer for a late harvest of warm-season crops. They'll do well until the first hard frost (below 30 degrees), usually in late November. Using the days to maturity on the seed packet, count back from our first frost date to ensure you have enough days for plants to mature.
Plant cool-season crops from July through September, depending on the plant. Consult a table of dates for planting vegetables in Oregon or talk to folks at your local garden shop. Until rains take over, you'll need to water young plants.
Crops like garlic, shallots and fava beans can overwinter: plant them in September and they'll grow slowly all winter for harvest the next spring.
Protect your plants
With veggies in the ground, pay attention to the weather forecast. Be ready for cold snaps with these easy strategies for protecting plants:
- Milk jugs with the bottoms cut off will protect single small plants.
- For a larger area, wire fencing covered with heavy-gauge plastic creates an inexpensive row cover.
- Even easier is a floating row cover, lightweight, breathable sheeting draped loosely over plants and anchored by rocks or soil.
A warm and sunny winter day can cook covered plants (unless you are using the floating row cover), so remove covers as needed, and to allow the rain to do the watering for you.
When the first hard freeze is forecast, harvest warm-season crops. Until then, they can keep growing in the sunny days of early to mid fall, with protection on nights when the temperature drops below 30 degrees.
Winters here vary from relatively cold with extended freezing spells, to mild enough that plants keep growing. With protection as needed, cool-season crops grow and can be harvested all winter long; or they slow and then put on a burst of growth when temperatures warm in late winter.
Use the ground as a refrigerator for root plants, like carrots and leeks, harvesting whenever you want them.