What hardworking gardener or farmer doesn’t relish the idea of time off? For us, winter is our vacation: a chance to relax, rest our bodies and minds, read, knit, sit by a warm fire and plan for days to come. I look forward to winter like a schoolgirl anticipating the summer holidays: long hours with no physical labor, just lounging and daydreaming. There are ways to facilitate this peace of mind by putting your garden to bed in a manner that keeps it productive during the cold months. I can rest even easier knowing that, although I’m not outside working, millions of garden helpers in the soil are, because I’ve taken care to protect and feed them over the winter.
1. Plan for Next Year's Garden Now
A good way to assist in winter preparation is to have next year’s planting plan in place by the end of the summer. Crop rotation is important for crops that can harbor disease or attract pests if kept in the same place year after year. In late summer, I begin to chart my garden layout for the following year, making sure I rotate the solanaceae (eggplants and tomatoes), curcurbits (cucumbers and squash) and especially brassica (cabbage and broccoli) families. I try to place nitrogen-hungry plants, like corn, where a nitrogen-fixing legume, like peas, grew the year before.
I sometimes plant a poorly drained bed with a deep-rooting cover crop or one that I know will add significant organic matter when it breaks down. Beds that have grown heavy-yielding crops get some time off with a thick topping of compost and amendments to replenish the soil. Regardless of your rotation, it helps to know where you want to plant spring crops when it’s time to get the seeds in the ground.
2. Plant Cold-hardy Crops
In the Pacific Northwest, autumn is called our "second spring.” This refers to the chance to plant cool-weather crops and reap another harvest before the days of winter set in. The daylight hours mirror those of April and March; soil and air temperatures are more conducive to rapid germination and growth, although it’s a challenge to keep the soil sufficiently moist during the August and September heat. It’s important to pay special attention to the watering and shade requirements of these cool-weather plants.
Before the first tree leaves even start to turn, you can plant cold-hardy crops such as spinach, cole crops (broccoli, kale, cabbage, brussel sprouts and kohlrabi), Asian greens (bok choy, pak choy, tatsoi), and beet and salad greens that, when started at summer’s peak, grow and thrive in the cooling days, rewarding you with some late harvests near winter’s onset. There are also crops that will hold through winter and start yielding in the earliest days of spring, such as overwintering cabbages, broccoli, onions, carrots, peas and fava beans. These are always welcomed when the cold and snow have been around far too long and I’m yearning to eat something not from the grocery-store produce section. You’ll pat yourself on the back for having planted these crops well in advance.
3. Feed the Soil
If you can spare room during the height of the summer season, plant cover crops on your soil. You don’t have to devote growing space exclusively to cover crops: You can underplant many cash crops with soil-nurturing plants and let them fill in and take over when the harvest is done. Many cover crops attract beneficial insects, helping pollination of the main crop and thwarting pests. Even the crops grown for harvest will benefit the winter soil in their own ways: Cut them off at ground level when they’re done growing, and leave the roots to decompose in the ground. They aerate the soil and create a beneficial habitat for all the organisms that populate it.
4. Dispose of Crop Residues—or Don't!
One way to help the soil is to properly dispose of your crops when they’re finished. You can decide which crop residues you need to clean up and which ones can be left in the field to rot, becoming mulch. Many of the crops killed by frosts are fine to leave in the beds. Squash plants rot in place, and their big leaves cover a lot of ground. Tomato plants do the same, but if you leave them, the fruits that went unpicked can produce thousands of volunteer tomato plants (which count as weeds to me) the following summer. I usually try to remove the tomato vines before they get mushy and put them in the compost pile. Lettuce, spent peas, cucumbers, eggplants and basil can be left.
Prune raspberry canes and burn the prunings to prevent disease spread. I cut them down and put them in my goat pen, where they get trampled and nibbled. Notoriously invasive, any canes that might sprout in the spring will be quickly consumed by the bramble-loving ruminants.
Cut and remove asparagus stalks from their beds. Sometimes I leave them in place until spring and then cut them down—they are lovely in a winter snowscape—but I have also cut them before the killing frosts, when they’re brown, for use on other beds as an extra aerating mulch. They do a good job protecting the soil and breaking down by springtime.
Bean and pea vines are easy to pull down, and goats love them, too. Be sure to cut them off at soil level, because the nitrogen-bearing root nodules will dissolve into the surrounding soil for the benefit of the next planting.
Grain crops can be harvested and the stalks cut down to create an instant straw mulch. Some annual grains die down without being cut, and you can plant directly through the remains. Annual rye does this, as well as releasing root exudates that are allelopathic to many kinds of weed and weed seeds. I grew winter wheat last year, and because it was too far along by the time frost hit, it was killed instead of holding until spring. However, it turned out that the residue it left on that bed created a haven for soil biota. When I raked it aside in the spring, the soil underneath was soft, black, and incredibly friable—it had a crumbly texture that looked almost like straight worm castings. Pulling back decomposed residues in the spring is exciting: It’s a good indicator of how well the soil was served and how close to planting you might be. You can leave these residues on top or till them when preparing for planting to help with the tilth of the soil.
5. Mulch, mulch and mulch some more!
The most important thing you can do for your garden or farm before winter sets in is mulch the soil. Plan to mulch your garden whenever possible in the fall, if you didn’t already do it earlier in the season. It’s best to mulch as soon as plants are in the ground. I heard a gardener say that bare soil is like an open wound on the skin of the Earth, and mulch serves as a bandage to help it heal. Sun and precipitation work to erode soil, baking and hammering the surface texture. Mulching helps conserve water and inhibit weeds that would compete with the crop. It regulates temperatures, keeping the soil cool on hot days and vice versa. It absorbs and blunts the impact of water droplets, whether from sprinklers or rain and hail. Mulch helps create an environment that protects the soil, sheltering the organisms, fungi and bacteria that inhabit it.
Using either organic or synthetic means doesn’t really make a difference, other than being able to incorporate organics the following spring versus having to remove and potentially dispose of the synthetics if they can’t be reused. Any type of mulch is multipurpose: It protects the soil texture and encourages the natural organisms to do their work. It enhances decomposition, forming compost at the soil surface, which nourishes the shallow feeder roots and the deeper root zones by gradual seepage. This compost, in turn, becomes more soil, adding back many of the minerals and nutrients that get taken out at harvest.
The list of things to mulch with is long: Synthetic choices are plastic sheeting, commercially manufactured "weed barrier” products, or the black silt fencing that’s thrown away from construction sites. None of those rot, but they still serve to protect and nurture the soil and its living systems. More natural options abound and include straw, hay, autumn leaves, wood chips, rice hulls, spent grain from brewing, dryer lint, pine needles, tree bark, sawdust, bundles of sticks or twigs, small coniferous tree branches, moss, or hair. I used our dog’s post-grooming hair around my tulips: It served simultaneously as mulch and a rodent deterrent with its predator-like smell. Less conventional (and less attractive) choices include newspaper or shredded office paper, herbivorous pet bedding, and torn cotton T-shirts, towels or bedsheets.
Years ago, I flipped over salvaged carpet and covered it with wood chips in an attempt to smother the weeds in my pathways: It has since rotted and left behind incredibly dark, well-drained soil that I seeded with low-growing clover and chamomile. All weeds that push through get topped by weekly mowing. Sometimes I’ll mulch with weeds that don’t reroot or don’t have seed heads—horsetail makes fabulous mulch and can be dropped right where you pull it. Or you can use leaves of the crops themselves: When I harvest rhubarb, I lay the cut-off—and poisonous—leaves around the base of the remaining plants.
Sometimes I cover the beds that I know will be growing early spring crops with finished compost and lay a strip of silt fencing on top of it all. The earthworms and other soil creatures incorporate the compost into the ground during the winter under the protective cover of the black fabric, and when I pull it back in the spring, the bed is almost in perfect condition for planting directly. Some years, I have put incomplete compost on the beds: rotting vegetables, vines, stems, asparagus fronds and cornstalks, topped with blackened, frost-hit tomato plants and chicken-coop cleanings. Slap a piece of landscape fabric over it, walk away, and uncover it in the spring to find finished compost and happy, naturally aerated soil with a few stray stems and stalks. One quick, shallow tilling, and you’re ready to go.
5. Give Frost and Snow Due Respect
The effects of winter on garden and farm soil can be harsh, and uncovered areas will be beaten down and compacted by rain, snow and ice. While many cold-climate gardeners swear by the freeze-thaw cycle, with frost heaving doing the rototilling work, for others, the soil doesn’t do anything but sit and take a beating. Our native Northwest soil, already poorly drained and predominantly heavy clay, gets battered by excessive rains and, at my high altitude, long-standing freezes bring no heaving to speak of.
The frozen ground can be good: It will kill a lot of bad bugs and larvae that overwinter in the soil, and it helps weaken many hardy perennial weeds. But covering the soil helps mitigate the devastation that nature can bring. Snow is actually one of the best things for a winter garden: It serves to insulate and cushion any hail or ice that follow. If the snow is followed by freezing rain, plants and soil are buffered from the ice layer by the snowy pillow. Mulch under the snow adds an extra layer of protection and insulation for the soil creatures deeper down. Winter cover crops also serve to protect the soil, buffer the blows of winter weather, and give the subterranean workers protection and food to keep working during the cold season.
About the Author: Kelly Wood heavily mulches the 55 raised beds of her CSA farm in Portland, Ore.
This article first appeared in the November/December 2009 Hobby Farm Home.