Summer is here and my garden is already producing basil, cucumbers, and summer squash. Right around the corner are beans and tomatoes. The edible garden is packed, full, bursting with plants quickly growing in the warm sunshine. After the frantic spring months of non-stop planting and garden projects we gardeners are ready for summer to kick back, relax with an iced tea, and reap the harvest of our hard-won spring labors.
Believe it or not, July is the time in Portland to think about your garden for a fall and winter harvest. I know, it sounds super crazy, right? It can be difficult to wrap your gardener brain around this concept of summer planting for a fall and winter harvest. Though it might feel counterintuitive to consider July and August as the months for planting an edible garden for fall and winter harvest, I assure you now is the time.
One important factor to consider if you would like to harvest cool season vegetables in the autumn into winter is our average first frost date. Here in Portland this average first frost date can wildly range any time between October 15 to December 15. Due to climate change this average first frost date has arrived later and later. Another consideration is in autumn and winter the sun is farther away and less powerful sunlight is reaching our plants. Combined with shorter day lengths plants grow much slower during autumn and winter even if temperatures are mild.
We want all edible crops to be at their harvestable maturity by our first frost. Most crops will stand in the garden during colder temperatures for harvesting, but not continue to grow. So, if we look at a broccoli plant that says 75 days to maturity, it needs to be planted in the garden around the first week of August to be harvestable by mid-October.
If you are like me, you have left no room in the edible garden to plant cool season crops in mid-summer. The garden is already packed with warm season crops like beans, cucumbers, peppers, squash, and tomatoes. If you desire crops for a fall and winter harvest this year, you have some options. Once you harvest your summer edible crops in September and October you can plant transplants/starts directly into the garden with a season extender like a cold frame, low tunnel, or frost blanket. If you have a greenhouse, even better! These techniques can warm up the garden to promote growing later into the autumn. Another option is to only plant quick maturing crops like lettuce, spinach, salad greens, radishes, scallions, baby beets and baby carrots.
Additionally there are overwintering varieties of crops like broccoli, carrots, and leeks that can be planted in September and October. They grow some in the mild weather of autumn, withstand winter's cold, and in the early spring growth kicks in. These overwintering varieties will rapidly provide produce in the early spring before spring planted crops are harvestable. Other types of autumn-planted overwintering vegetable crops are fava beans, garlic, and shallots.
Some crops for a fall and winter harvest have very long days to maturity and require planting in the garden in July. These are Brussels sprouts (starts), leeks (starts) parsnips (seeds), and rutabaga (seeds).
Crops to plant by direct seeding in the garden in August: Beets, carrots, chervil, cilantro, endive/escarole, florence fennel, kohlrabi, lettuce, mache/corn salad, peas, radishes, scallions, spinach, and turnips
Crops to plant by transplants/starts in the garden in August: Asian greens, broccoli, cabbage, cauliflower, chard, collards, kale, mustard greens, parsley, peas, radicchio, and scallions.
In my upcoming book The Gardening Goddess Guide to Edible Gardening in Portland I have an extensive chapter and planting guide for fall and winter harvest.
Here in our mild maritime northwest climate it is absolutely possible to grow some edible crops year-round. If you are aiming for some level of self-sufficiency from your own garden this is exciting news! This year I am planning to grow collards, chard, fennel, lettuce, mache, kale, peas, potatoes, and scallions for a fall and winter harvest.
If you are ready to learn more here are two excellent resources specific to our climate:
Winter Gardening in the Maritime Northwest: Cool Season Crops for the Year-Round Gardener, 5th Edition by Binda Colebrook, 2013
Also check out these excellent non-regional resources from my favorite year-round gardening experts: The Year-Round Vegetable Gardener by Nikki Jabbour, 2011
and The Winter Harvest Handbook by Eliot Coleman, 2009
I can't wait to hear what you are going to plant for a fall and winter harvest. Please let me know if you have any questions.
A selection of cool season crops for fall and winter harvest