Cold Weather Gardens: A Winter’s Tale
Building a Better World One (Winter) Garden at a Time
The arrival of autumn induces the deep-rooted need for hibernation, albeit in the most human of ways. Our cravings for salads and panini suddenly seep away, replaced with a longing for roasted squash and green chile stew or whatever late summer harvest your youth was filled with. For gardeners Autumn brings with it the joy of harvest and the optimistic planning of what’s to come; but there is another type of gardener, the one that stares down the impending frost and defiantly rifles through their seed stores for the broccoli, kale, an brussel sprouts daring the winter to bring the worst. Here are some tips if for you to join the winter garden squad this year.
Make a Plan
Cold Frame? Low-Tunnels? Greenhouse? There are plenty of options for all budgets for a successful winter garden, but all of them require capturing and holding heat. The soil and air temperature are equally important, and managing temperature is the most difficult task of the winter gardener.
Cold frames are the simplest way to manage a winter garden. You can make them simply by constructing a box with hay bales and covering it with an old window or polyethylene sheets, or you can construct a lid for your raised bed. Soil in raised beds stays warmer in general, but if you grow in ground the hay bale technique will help insult the air around your plants and in the ground. Just remember to remove the cover on warm sunny days or you run the risk of cooking your plants.
Low tunnels are a great option if have an in-ground garden, have a reliable irrigation system, and trust that your plants will need little daily care. Low tunnels are essentially single row or raisewd bed hoop-houses. You can purchase ready-to-go tunnels, or just use pvc tubing or wire to create the form, then cover with polyethylene sheeting. Use bricks or logs to hold the sheeting in place for easy access to plants, and to quickly open the tunnel on warm days.
Greenhouses are the easiest, most reliable way to grow in the winter, but can be difficult and expensive to construct, especially if space is limited. Ranging from very simple frames with polyethylene sheeting to exquisite temperature-controlled glass houses, greenhouse gardening can be as simple or complex as you make it (or as your budget allows). Depending on your greenhouse se- up you will be able to enjoy fresh summer vegetables year-round. Gardening in a home greenhouse system will generally require growing in pots, so if you’re unaccustomed to container gardening putting up a greenhouse is a great opportunity to add a new depth of color to your green thumb.
Start Early, But Not Too Early
In New Mexico with the warm and long autumn days it’s not uncommon to harvest summer vegetables up tol the first frost, so planning and executing your winter garden alongside your late summer/ fall crops can extend the growing season. Albuquerque is in Zone 7, usually receiving a first frost around November 15th. You will want your winter vegetables to be established at least a few weeks before the first predicted frost. Transplanting indoor starts into a winter a garden is risky if not a fools’ game, as the temperature shock can stunt or kill your plants. Soil thermometers are available at most garden centers, but a kitchen meat thermometer works just as well. Most frost hardy vegetables will need the soil to be at least 40°F to germinate.
Have the materials ready early as well: today’s 55° low could be tomorrow’s 45° high. Covering the garden too early can lead to moisture build up and fungal problems, not to mention cooking the plants, but you want to be ready to cover it at the first sign of frost. Insulate your drip system and all pipes that are connected to your irrigation system at first frost as well, you don’t want to wait too long and have an ice problem in your watering line.
Health and Maintenance
Adding a bit of compost to your beds in early-mid autumn will replenish the nutrients lost over the spring and summer, as well as reintroduce fresh microbial communities to keep your soil food web strong and healthy through the winter. After your bed is prepared nothing will help your winter garden more than mulch. A thick (4-6”) layer of organic mulch will insulate the soil and your plants. The fallen leaves that you raked up will make a great base layer, but leaves decompose very quickly so you’ll want a hardier material such as Soilutions Forest Floor mulch or straw.
Keep an eye on the weather. Cold fronts develop quickly and unexpectedly. Keep old sheets or burlap sacks handy for extra insulation if a polar vortex forms. Before the coldest nights, water a little heavier than normal and keep an open jug of water or two in with your plants during the day to allow moisture to build up to trap heat.
Finally, choose the right vegetables! Even though you take great pains to insulate your winter garden, chances are tomatoes and okra are out of the question. Kale, broccoli, brussel sprouts, beets, lettuce, carrots, cabbage and parsnips do great though, and it’s a great time to grow extra onions and garlic for those winter stews.