RALEIGH, N.C. — Winter is the time when we generally think of rest and recovery for ourselves as well as our gardens. Most home gardeners leave their garden soils bare over the winter and wait for the start of spring for planting. This does nothing to improve the soil quality over time and may lead to erosion. Instead, mulch the garden with a layer of plain cardboard covered by compost or fine-textured mulch to prevent winter weeds from germinating, and add organic matter. Over the winter these materials will be broken down by soil microbes and invertebrates.
Another option is growing a green mulch by planting cover crops during the winter season. These are crops that you do not intend to harvest for consumption. Over the winter the plants will protect your soil from harsh freezing temperatures and can be killed off and worked into the soil at the end of winter. By spring planting, the plant material will be broken down, adding organic matter and nutrients to the soil. Cover crops are selected based on the multiple benefits that they provide. If you know your garden plan for spring includes anything in the brassica (broccoli) family, then plant something that fixes nitrogen, such as Austrian winter peas. Cover crops can interrupt disease cycles if they are not in the same families as your other vegetable crops. Some gardeners even plant long-season plants (such as garlic) that require chilling hours rather than leaving their gardens bare. There are plenty of options that will benefit you and your soil over the winter rather than leaving it barren. For more information, see the “Organic Gardening” chapter of the North Carolina Extension Gardener Handbook. —
–N.C. State Extension