Many winter crops do well in our region, including purple sprouting broccoli. Plant now for early spring harvest.

Photo courtesy Violet Locati

Barbara Faurot

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Our maritime climate is well suited to year-round gardening and year-round harvesting. Whether you have an established kitchen garden or are just getting started, mid-summer is a perfect time to plant a variety of winter and early spring crops. 

Planting now — not too early, and not too late — allows plants to reach a good size before the first frost slows their growth. Many crops can be harvested throughout the winter, while others will go dormant and then be ready to enjoy in early spring.

In mid-July, plant beets, rutabaga, radicchio, kohlrabi, quick-growing cabbage varieties, and hardy chards. From now until early August, you can sow kale, collards, winter radishes, and other hardy leafy greens.

Some large winter vegetables like purple sprouting broccoli, Brussels sprouts, winter cauliflower, carrots, and parsnips prefer to be planted from seed in early July. So if you haven’t planted these yet, look for winter plant starts at local nurseries and transplant them into your garden in early August. 

Whether you are starting from seed or from small started plants, be sure to select winter varieties suited to the cooler, shorter days ahead. 

If you’ve never planted for a fall-winter harvest, or if you have students at home in search of a fun summer project, greens such as kale, spinach, chard, and leaf lettuce are a good place to start. Choose the warmest, sunniest place in your garden to take advantage of sunlight as the days grow shorter. Leave extra space between plants to promote air circulation and make it easier for the plants to access nutrients as the soil cools. Plan for consistent watering through the dry summer, adjusting as fall rains arrive. 

In addition to planting in the ground, you can sow hardy greens and other winter crops in raised beds or pots. You can even sow the seeds in pots where tomatoes or other summer crops are growing now. The organic matter from the tomato plants will help enrich the soil as the winter crops get established. 

Try different varieties and experiment to learn what works best. Use information about pests and beneficial garden insects to your advantage. For example, Nita Wester, WSU Extension Master Gardener and co-instructor of WSU’s Growing Groceries class, found that growing winter carrots in pots worked better than in the ground. To protect the plants from the carrot rust fly, completely enclosing the bed with cover cloth was the most sure-fire prevention strategy. 

Nita learned that putting a “fence” of cover cloth around the pot to a height of 4 feet worked, as carrot rust flies have a low flight range. Females are more likely to fly in the afternoon, so removing barriers in the morning for weeding or thinning reduces the risk that the eggs will be deposited. 

“Certain winter varieties just seem to do well here,” adds Nita. 

“Drunken Woman Frizzy Headed Lettuce” is one example. No one seems to know the name’s origin, but it’s a savoy type with crisp, red-tipped leaves. Mache is another leafy crop that thrives in our region, germinating when it’s cooler, and never getting bitter. Purple sprouting broccoli is also a local favorite for early spring harvest. 

To make room for new plantings, remove spring and early summer crops that are finished, and use these spent plants as mulch. Leave the crop roots in place to decompose and add organic matter and nutrients to the soil. 

Fast-growing crops like spinach, radishes, and leaf lettuce can be grown in succession. But to minimize the risk of soil-borne disease, avoid planting crops from the same family in the same bed in succession (for example, broccoli, kale, and cabbage in the brassica family). Keep an eye on self-sowers like kale, cilantro, and dill to ensure they don’t interfere with your succession plan. 

If you’re starting from seed, it’s a good idea to shade the new seedbeds until the seeds germinate. Some crops such as carrots and lettuce may not germinate if the soil is too warm. Even heat-tolerant seedlings can fry in the hot sun before their roots can develop and reach cooler soil. An opaque cover—shade cloth, old newspaper pages, old sheets, towels, burlap, or light coverings of straw or grass clippings—can be used to protect the seedbed. Remove as soon as the tiny plants emerge. Continue to water regularly and provide some shade until the plants become established. 

While a hard frost in the soil is rare in our temperate climate, once the plants are established, add a layer of loose mulch to increase organic matter, moderate soil temperature, preserve moisture, suppress weeds, and prevent erosion. By December, add a heavy layer of mulch to protect overwintering plants and root crops from unpredictable weather. 

For details on crop varieties, planting dates, and tips for success, the Extension Services at WSU, OSU, and University of Idaho offer a free publication, “Fall and Winter Gardening in the Pacific Northwest”: 

https://catalog.extension.oregon
state.edu/sites/catalog/files/project/pdf/pnw548.pdf.

The nonprofit Seattle Tilth also offers a helpful planting and harvest calendar: https://tilth.org/app/uploads/2015/02/OT_PHCalendar_Archive.pdf.

Master Gardeners at the online Plant Clinic host weekly live Zoom sessions from 12:30 to 2:30 p.m. Mondays. To make an online appointment or submit a written question, visit http://jefferson.wsu.edu/plant-clinic.

(Barbara Faurot is a Jefferson County Master Gardener and Master Pruner, working with other volunteers who serve as community educators in gardening and environmental stewardship.)