Winter Vegetable Garden Growing Guide

With a few steps and some planning, you can enjoy garden fresh vegetables all winter.

Cold Frame Permanent Structure for Hardening Plant

Cold Frame Permanent Structure for Hardening Plant

A cold frame can help you grow vegetables in cold weather and give you a head start with seedlings.

Photo by: DK - Gardening Step by Step © 2011 Dorling Kindersley Limited

DK - Gardening Step by Step , 2011 Dorling Kindersley Limited

A cold frame can help you grow vegetables in cold weather and give you a head start with seedlings.

One of the latest developments in our culture’s popular revival of backyard food production is winter vegetable gardening. While home grown tomatoes in January are still a bit of a fantasy for most of us, you can grow a wide array of cold tolerant crops with a degree of effort and planning not much greater than that given to warm season gardens. These few tips will provide some insight into what it takes to fill in the calendar with backyard produce in the not-so-dead of winter.

Provide a Good Environment

As is always the case with gardening, winter vegetable production starts with the garden plot itself. Now that the leaves are off the trees, and with the changed angle of sunlight, the summer garden spot may or may not provide enough sunlight.The minimum requirement is 6 hours of direct sunlight, although more is better. Soil will absorb heat while the sun shines and radiate that warmth to the plants once the sun is down.

The soil must provide a good balance of moisture retention and drainage. The plot should have lots of compost incorporated prior to planting. Many formulations of fertilizer that work wonders in warm weather are not effective in winter. Compost helps provide good soil structure, and also provides plant food in a way that makes it available as the crops require.

As considerations are made for protecting crops from cold, keep air circulation in mind. Good air movement around plants helps avoid problems with disease and insect pests that are still active in the cold. Good watering habits are also critical, for the same reasons. Water in the mornings, allowing as much time as possible for foliage to dry in the daytime.

Keep the Soil Warm

The most cold hardy crops will benefit from the relatively warmer soil. A few extra degrees can make a huge difference on the margins of not only life and death, but also growth rate: the longer the plant grows without stopping, and the quicker it starts growing again. Keeping the soil insulated will help with this effort. Black plastic mulch attracts the sun’s heat to maintain a warmer soil temperature. Unfinished compost provides its own heat as it continues to decompose, and so it makes a good winter mulch. A thick layer of mulch will help to insulate the ground from the freeze-thaw cycle that can damage roots and heave carrots, turnips and beets out of the ground.

Put a Lid on It

Wait as long as possible to cover the tops of winter crops. Some cold exposure is good for flavor, and the exposure to the elements provides great air circulation and free water when it rains. A little cold also helps to harden the plants off for the winter to come. When the forecast is for consistent freezing temperatures, or frozen precipitation, that is your cue to put a lid on it. With mulch already in place this can be as simple as a row cover in a mild climate where the weather will shortly warm. In areas with longer, colder winters several winter-long options are available.

Cold frames are rigid frames, usually made of wood and plastic or glass, that act like miniature greenhouses. Normally they are above ground, however when dug into the ground they obtain more consistent temperatures. By adding bottom heat (either with electricity, or the old-fashioned method of covering a layer of fresh manure with a thick layer of straw), the cold frame becomes a hot bed. The cold frame is traditionally used for longer term crop production through the winter. The hot bed is a good way to start seedlings in late winter before it is warm enough to transplant them into the vegetable garden.

Tunnels are unheated greenhouses constructed over the garden beds. They provide similar benefits as cold frames, but serve much larger areas. A practical, inexpensive way for homeowners to do this is by bending PVC pipes over the garden bed, framing in the ends (one with a door), and covering this framework with UV resistant plastic.

Areas receiving the coldest weather may require two of these features in the same area. For instance, you could build cold frames in the garden area and then enclose them in a tunnel. Another option would be to use row covers inside the tunnel when a deep cold snap hits, then remove the row covers when normal winter weather returns. Once you have covered your crops, be cautious when the weather becomes mild. Unseasonably warm temperatures, particularly after some cold weather has hit, will cause crops to mature too early, in essence causing the whole system to “backfire.” Be sure to ventilate the structures, and remove row covers in mild weather (daytime temperatures above 45, night temperatures above 35).

With some planning and a little effort, growing vegetables in the winter is not a farfetched idea. Start early and provide good soil, plenty of sunlight, enough moisture, and a bit of insulation to keep cold hardy varieties in production. Stoke your gardening fire and enjoy the veggies of your labor this winter!