Right now, the Bay Area winter may be gently nudging or loudly banging on your door. If you’re a gardener, the transition into the cool season can seem abrupt and disappointing, but with steps taken now, you can boost plant growth and keep your beds productive through the winter months.
1. Mulch for Warmer Roots
One dramatic way to buffer root temperature is with mulch. Laying down straw hay, wood chips, or cocoa hulls two to four inches thick over the garden bed creates an insulating “skin.” Additionally, this helps feed the soil as the force of driving rains help decompose the mulch, breaking it down to finer particles, which help build the fertility of the soil.
2. Make Wind Breaks
If you are buying hay bales for garden mulch, get extras and try stacking them vertically on the windward side of your garden to break the force of the weather. These bales are then available to spread for mulch as needed. Another way to break the winter wind is to build trellises on the north edge of growing areas, where they will not shade out the sunlight from your beds. I repurpose old, broken hand-tool handles as trellises, and use discarded pallets as mini-fences on the northern edges. I love to watch pea and bean vines wiggle their way up and over the pallets. These vertical structures add calculable real estate to your growing area.
3. Cover Crop with Edibles
Have you ever sat at the window or bundled up on the porch with a cup of tea and watched a winter storm pelt the bare soil? This is erosion and soil compaction in action. Green mulching protects the soil from such conditions, adds fertility, and simultaneously produces a crop you can harvest for winter food. I like to use a mixture of fava beans, clover, and snow peas to build a multi-story nitrogen-fixing soil amendment. Fava shoots and flowers are lusciously nutty in flavor, and you can use them as you would spinach. Snow pea shoots are actually becoming quite popular as an edible garnish, their curly tendrils adding visual interest to a soup or salad. Even clover can be a stop on your weekly salad-harvesting tour around the garden. Come spring, you can hand-till the residues from these crops into the soil.
4. Plant the Margins with Catch Crops
A good way to increase harvests from your winter garden is with catch (or snatch) crops. These are quick-growing plants that can fit into spaces around and between your slower-growing main crops. I like to use radish, turnips, beets, lettuce, and arugula for this purpose, as they will happily grow in the understory and edges of my main plantings. When the catch crops get large enough to disturb my broccoli, carrots, endives, Swiss chard, collards, and kale, I know it’s time to harvest and re-seed them.
5. Cut and Re-Grow
You don’t always have to take up the whole plant when harvesting. During the cool season you can scissor-cut leaves from arugula, lettuce, parsley, and scallions two inches up from the ground and let the plants re-sprout. Another cut and re-grow strategy you may have seen used with kale, chard, cabbage, and lettuce is radial harvesting: Single outer leaves can be cut for the kitchen as new leaves sprout in the center of the plant.
6. Garlic Rites
Garlic, a nine-month crop, benefits from growing through the cold months. While you can plant garlic in spring for fall harvest, winter-grown garlic produces larger bulbs. I recommend the elephant garlic variety. Planting garlic bulbs as you put the beds to bed is a lovely ritual that connects the end of one year’s growing season to the beginning of the next.
7. Keep the Heat
Have you ever wondered why some gardeners have large jugs full of water or basketball-size boulders set among their plants? They do this to increase thermal mass. It helps to slow nighttime cooling of the soil with a slow release of heat that’s been trapped during the day. Likewise, gardeners learn the advantage of planting along south-facing walls, where it can be five degrees warmer during the coldest nights.
8. My Up-Cycled $200 Greenhouse
In an effort to get my spring veggie starts going earlier, I decided to invest in a cost-efficient greenhouse. For $80 I purchased a used steel carport frame, and for another $120 I bought enough 6-mil polyethylene plastic sheeting from a commercial greenhouse fabricator to cover it, making a 10-foot by 20-foot greenhouse. I then collected discarded pallets and constructed sprouting tables. A greenhouse will enable you to start tomato and pepper sprouts as early as February, giving a boost to your garden come spring. You might find that tomato plants started this way can produce later into the fall.
Joshua Burman Thayer is a permaculture designer and educator uniting ecology with aesthetics to create beautiful, productive natural systems that foster healthy ecosystems and bountiful community-scale production of organic food. He has written for Mother Earth News and Edible Silicon Valley. Learn more at his website, nativesungardens.com. Follow him on Twitter at @nativesungarden.
Cheryl Angelina Koehler is the editor and publisher of Edible East Bay and author of Touring the Sierra Nevada, published by University of Nevada Press.