Yes, Virginia (and Maine!), There are Fresh Greens in Winter

There are many reasons to consider growing your own food. Our current system uses enormous quantities of petrochemicals (which are included in fertilizers and pesticides, meaning we end up eating them) as well as for farm machinery, shipping, refrigerated storage and packaging. Contamination can spread quickly and for certain foods, largely untraceably. And genetic modification, depending on where you live, may be sanctioned by authority and does not have to be disclosed to the consumer.

Yes, you can grow your own food. But what about winter, if you don’t relish the idea of consuming produce grown halfway round the world? You can grow food for winter harvesting and eating—with the right information, planning and attentive care.

What Grows in Winter?

In a temperate enough climate, any number of crops may extend their yield as late as November, including tomatoes, berries and beans. A “rolling harvest” that picks the most mature fruit as it develops, encourages development of new fruit for a longer period. (Some fruits—apples, pears, persimmons, citrus—are harvested in winter, but require a summer growing season. They can be part of a general strategy for year-round fresh food, but fall outside the scope of this article.) Foods that actually grow during the winter—planted late summer through late fall with harvests in winter or early spring—include the following:

• Cruciferous vegetables: One of the most cold-tolerant vegetable families provides specific health benefits, including antioxidants, anti-carcinogenics, high fiber. They also come in a great deal of variety. Get ready, because the list is long!
  • The dense, adaptable cauliflower
  • Broccoli and its close cousins, which are:
    • Roots such as radishes, turnips, kohlrabi, rutabaga;
    • Leafy greens such as arugula or rocket, kale, bok choy, collards, mustard and turnip (again!)
    • “Headed” greens such as Brussels sprouts and cabbages;
    • And even herbs and oil plants, including mustard seed, various cresses, horseradish and canola or rapeseed.

A note about dietary crucifers: although among the healthiest of vegetables in many ways, dietary crucifers in excess can interfere with iodine absorption by the thyroid. There is also a human genetic factor that can make these vegetables distasteful to some. The first would be Brussels sprouts’ reputation for bad taste and texture may be avoided by not overcooking. Crucifers are also attractive to aphids.

• Other root vegetables: such as beets, carrots, parsnips and Jerusalem artichokes. (These, like the crucifers grown for their roots, are attractive to burrowing mammals.)
• Other greens: chard, spinach, radicchio, endive, chicory, celery, and dock or sorrel.
• Squashes, both winter and “summer”.
• Beans, peas, and members of the onion and garlic family, including scallions and leeks.
• Grains with a dormancy period, such as oats or winter wheat; these can be planted in late fall for an early spring harvest.
• Perennial herbs: oregano, marjoram, basil, cilantro, parsley, chives, fennel.

Many variables affect planting success:

• How cold does it get in a particular planting’s “hardiness zone”—and when and for how long?
• How warm does the planting climate get—again, when and for how long?
• How good is the soil? Is it rich, depleted, sandy? Does it both retain and drain water?
• The myriad individual requirements of particular plants.

Of these, issues of cold and wet may be the most obviously relevant to winter gardening. As we’ll see, the other factors interact with those as well.

Cold

Cold is not inherently the gardener’s enemy. Some crops like winter wheat require it. The cold can serve in some climates as an outdoor refrigerator/freezer: leeks and some root vegetables can be left in the ground and harvested as needed; if a large and quick harvest is needed, items like green tomatoes can be cellared rather than immediately canned. Working a garden on a cold day may require more concerted effort than gardening in spring; it may also precipitate a certain awareness and efficiency, as you monitor which plants need to be mulched, wrapped, watered, or even have their coldframes or other structures vented lest they get too hot! (In any event a cold day in the garden is likely to be more invigorating than an enervating hot day when you have to water or else!)

The hardiness zone is a rough guide to which plants will succeed or fail at the extreme cold end of a given climate belt. Although no guarantee of success, it can help eliminate certain choices for a planned planting, or determine what measures might be required to moderate the effects of cold. (Gardeners in the western U.S., subject to many more variations due to the mix of mountainous, desert, and coastal climates, may find more useful the greater range of variables in the Sunset Magazine climate zone system.)

Wet

Much winter damage may be due not to the temperature per se, but the interaction of cold and water. Winter across the country may be dry or wet; if wet, precipitation typically takes one of the following forms (excluding the wild card of hail, which may strike in any season):

Frost

A frozen precipitate that can coat the ground and vegetation at freezing temperatures and below, is the first and most obvious danger to plants. What is possible to grow and how much effort it takes to grow it, will largely be determined by the normal cycles of frost and thaw, as documented in any number of sources, such as The Old Farmer’s Almanac. Although a few areas of the U.S. may not have a frost in any given year, typically the first autumn or winter frost falls from September to December. Planting for winter harvest means knowing the typical first “hard frost” (a.k.a. “moderate freeze”) date, and getting seeds or starts in the ground—late summer to early fall—in time for them to mature before being done in by the weather. Not all frost is deadly, certainly not to all crops—some winter crops seem to reach their full flavor only when exposed to a few frosts.

Rain

Precipitation in general may be “good for the crops,” but harsh, torrential rains can wash away seeds or simply leave the ground too soggy for germinating seeds to take hold. Too much rain is harder to compensate for than too little. Raised beds may provide a greater degree of ground moisture control, but also greater soil exposure to the cold. In the northwestern rain forest, the combination of wet winters and diminished hours of sunlight require extra vigilance against mildew, slugs, and root rot. For exposed plants, the cloth used for summer shade may be used as a rain screen for those plants or others in winter, or one of the more elaborate structures described below may help.

Snow and Ice

Either can simply crush plants or even collapse the garden structures meant to protect winter crops. On the other hand, a reliable snow cover is better for the winter gardener than less predictability; ground temperature stays more even, and roots are not subjected to repeated cycles of freeze and thaw.

Cheating Mother Nature

To some reasonably predictable degree, garden shelters can modify weather effects. Depending on the ground available, the overall climate or microclimate, and the particular plants in question, these can range from the “cloches” of French gardeners (placed over individual plants or groups of small plants, and ranging in size up and down from about a gallon) through the more familiar cold frames through “hoop houses”, “high tunnels” and on up to greenhouses. One Green Generation gives a good overview of these, including construction using scavenged or repurposed materials, along with a reading list for more in-depth research.

Materials, Tools, and Planning

Seeds, of course, like seed catalogs, are available throughout the year. Small-town nurseries, though, which can be one of your best sources for information as well as supplies, may close seasonally. Less dramatically, hardware stores may carry fewer supplies in the conventional off-season or what they have may be harder to retrieve. Although lumber or salvage yards may carry materials for building a cold frame year-round, collecting and assembling those materials is going to be a lot more practical while the weather is still mild. Research and planning are essential.

Experience and Experiments

Although there are many comprehensive sources for information, the best sources may be local: neighbors who garden, of course; your nursery; and Master Gardeners, a cooperative program that brings together extension departments from agricultural schools with gardening and teaching volunteers. Local Master Gardeners may publish, in print or online, a planting schedule based on local experience and environment, taking into account such variables as humidity, microclimates, or soil conditions. Remember, though, these kinds of publications (and conversations) provide basic guidelines. You should feel free to take some portion of seeds or starts from each planting to “push the envelope” a bit, trying them a little earlier or later to see how they do, and then harvesting seed from the most successful experiment. Before you know it, you may be a master gardener yourself!

Resources

One Green Generation chronicles year-round produce gardening in California and Seattle, and includes reader feedback and updates on winter gardening in colder climates, as well as an excellent reading list.

The American Horticultural Society publishes a list of Master Gardeners programs and other resources.

The National Gardening Association has useful information on its page Edible Landscaping.

Other articles in this issue:

• Vegetable Storage: Getting to the Root of the Problem
• Hunting Preparation for the Survivalist in You
• Heating Options for Your Home

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