Note: This is a general guide and is not climate zone specific. We will discuss tools and techniques to combat frost and freeze conditions, cold-hardy perennials and annuals, and winter soil building. Not all species named are hardy in all zones. Please see the USDA Plant Hardiness Guide for more information.
Freezing temperatures are possible in every zone up to USDA zone 10 – in other words, nearly everywhere in the United States, it’s possible that you will, at some point, need to take measures to protect plants from cold damage during the winter. In very cold locations, particularly where snowfall sticks and accumulates, very few winter crops are possible outside of greenhouses, if any. However, there is much you can do during the fall and winter to improve spring and summer yields of all crops. In warmer areas, a lot of things that you might not have expected can thrive in the cooler, wetter winter conditions.
In areas where there is a lot of snow accumulation, you can support a winter garden by growing inside of a greenhouse. Unless you want to also run electricity for heating and lights to your greenhouse, it is still recommended that you grow season-appropriate plants. Greenhouses come in and endless variety of shapes and materials, each with its own advantages and disadvantages, but for winter gardening some of the more important things to make sure you have are a steeply pitched roof that easily deflects rain and snowfall, and a wrapping material that discourages the accumulation of moisture on the interior of the greenhouse, which generally means a double layer with an air-gap. This is available in both plastics and glass.
Passive heating for a greenhouse can be accomplished by lining at least one side with black drums filled with water. These will accumulate heat during the day and release it as they cool at night, preventing freezing temperatures in the immediate vicinity.
For regions that only experience frost and light snowfall during the coldest times of winter, a frost cover draped over sensitive plants at night is typically all that is needed. There are as many configurations for frost covers as there are greenhouses, but what they all have in common is they are a barrier, any kind of barrier, between freezing moisture and the tender leaves of your plants. You can buy frost covers from farm and garden supply centers shaped specifically for row crops, trees, specific sized pots, or you can improvise. Most home gardeners just use old bedsheets, plastic tarps, painter’s plastic, etc.
What to Grow in Winter
What should you grow in Winter? That depends on whether or not you intend to eat it. There are lots of things that I, personally, grow in winter, but not for the purpose of eating them. I mostly use cold-hardy plants as ground-cover, nutrient-cyclers, and bio-accumulators. That being said, you can also eat most of them, if you’re feeling rabbity.
Read now: Delicious Winter Garden Borscht
- Brussel Sprouts
Read now: How to Make Real Sauerkraut
Other Food Crops
- Swiss Chard
Herbs and Perennials
- Kiwi, especially Hardy Kiwi
As I previously mentioned, though I do occasionally graze in my winter garden for beets, carrots, radishes, greens, and herbs, I mostly just weed-wack them down every time they get over knee height to create a thick, winter mulch. When my neighbor’s trees lose their leaves all on one day, I’m over there with a rake stealing all of those delicious nutrients before the yard service takes them away. In fall, I throw down cover-crop seed of the annual legume (peas, clovers, vetch) variety, which sprouts just before the frost but survives the winter and blankets the yard in green all throughout, and attracts birds and bees in spring. If you get winter snow accumulation, lay down as much biomass in fall before the snows come, and your spring soil will be rich and dynamic.
Happy winter gardening!