What Are Cold-Tolerant Vegetables?

Vegetables, like other plants, vary in their sensitivity to cold and heat. Oftentimes their levels of tolerance are described as tender, semihardy or hardy. Throughout much of the United States, many vegetables grow better in an early spring or fall garden than they do during the hotter parts of the summer.

The hardiest of vegetables, or those that tolerate hard frosts, include the cole crops, or natural varieties of the species Brassica oleracea. Broccoli (Brassica oleracea var. italica), kale and collards (Brassica oleracea var. acephala), kohlrabi (Brassica oleracea var. gongyloides) and cabbage (Brassica oleracea var. capitata, tuba and sabauda) are all examples of cole crops. Onions (Allium cepa), spinach (Spinacia oleracea) and turnips (Brassica rapa rapa) can also handle a hard frost without damaging the leaves or roots.

Tender vegetables are those which are damaged by even the lightest frost. Tomatoes (Solanum lycopersicum), beans (Phaseolus spp.), peppers (Capsicum spp.), watermelons (Citrullus lanatus) and cucumbers (Cucumis sativus) are all tender vegetables and do best when you grow them during the summer. Semihardy vegetables can tolerate a light frost; this list includes carrots (Daucus carota), endive (Cichorium endivia), lettuce (Lactuca sativa), parsnips (Pastinaca sativa) and potatoes (Solanum tuberosum).

As with summer vegetable gardens, the planting dates for spring gardens varies depending on the length to harvest times for each variety you plant. Some crops take only a couple of weeks to reach maturity; others may take well over a month. For most cole crops and other hardy vegetables, you can plant two to three weeks before the date of the average last 32-degree freeze. Some of the extra-hardy vegetables, including turnips and spinach, can go in the ground as soon as the soil is workable in early spring. Once you have harvested your spring garden, you can plant quick-growing summer vegetables in the plot.

Fall gardens often offer gardeners a direct benefit: you can plant in the garden plot where your already-harvested summer vegetables grew. Direct seeding is typically used for fall gardens. Seed most hardy and extra-hardy plants in late summer, typically August or September. Some crops can overwinter in even the snow-covered Midwest. Rows or tunnels of metal hoops and plastic can protect crops throughout the winter while also providing a warming effect. For winter-hardy root crops, the snow cover actually acts as an insulator for the soil.