Preparing Your Garden for Frost
While freezing temperatures are not predicted for the coming week in the central NC Piedmont, they are not far away. A few locations in our area have already flirted with frost, but a true killing freeze, in which temperatures fall to or below 28 F degrees, has yet to occur. The first killing freeze in our region typically occurs sometime between October 21 and October 31. Get the most from your garden by preparing for frost before it is too late.
Warm Season Crops
Frost will bring an end to any summer crops still producing in your garden. If frost is predicted, make a final harvest of tomatoes, peppers, cucumbers, squash, zucchini, eggplant, and okra. To make the most of this late season bounty, store crops under the proper conditions. Most summer crops store best in perforated plastic bags at 55 degrees and will last up to a week under these conditions, though peppers may last longer. Avoid storing summer vegetables near apples, bananas and tomatoes, which release ethylene, reducing the shelf life of nearby fruits and vegetables.
Partially ripe tomatoes and green tomatoes that have reached full size can be harvested before frost and brought indoors to ripen. For best results, wrap each tomato separately in newspaper and store them at 55 F to 70 F. Tomatoes stored in this manner can last 3-5 weeks. Be sure to inspect each week for ripeness and remove any fruits showing signs of rotting. Keep in mind that once harvested tomatoes will continue to soften and turn color, but will not develop flavor so leave fruits on your plants as long as possible for maximum flavor development.
Be sure to dig sweet potatoes before frost. Following harvest, sweet potatoes should be cured by placing them in a moist, warm (80-85 degrees) location out of direct sunlight for a week to 10 days. Once cured, store them for winter in a dark, cool location (55 degrees) where they will not freeze.
Cool Season Crops
Most cool season crops growing in your garden will tolerate temperatures as low as 28 degrees. In fact, frost and cooler temperatures actually enhance and improve the flavor of many cool season crops. Kale, collards, cabbage, Brussels sprouts, spinach, Swiss chard, carrots, onions, garlic, and leeks, are among the hardiest of cool season crops. These vegetables are fine outside during most winter weather but will benefit from being covered in extreme cold.
Cool season vegetables such as lettuce, broccoli, cauliflower, turnips, beets, Chinese cabbage, kohlrabi, radish, rutabaga, and beets will tolerate frost but may be damaged if temperatures stay below 28 F degrees for several hours. To extend the harvest of these cool season vegetables into winter, cover them with row cover or a cold frame when temperatures are predicted to fall below 28 F.
- Harvesting vegetables, from Cornell Extension:http://www.gardening.cornell.edu/factsheets/vegetables/harvestguide.pdf
- Storing vegetables, from Minnesota Extension: http://www.extension.umn.edu/distribution/horticulture/dg1424.html
- Optimum Vegetable Harvest Times, from NC Extension: https://www.ces.ncsu.edu/depts/hort/hil/hil-8108.html
- Using Row Covers, from Gardener Supply Company: http://www.gardeners.com/Row-Covers/5111,default,pg.html
- Cold Frames, from Missouri Extension: http://extension.missouri.edu/publications/DisplayPub.aspx?P=G6965
Use Extension Search to find research based information from Cooperative Extension systems across the U.S.
Visit your local Cooperative Extension office to learn more about gardening and landscape care. Go to https://www.ces.ncsu.edu/local-county-center/ to find your county Extension center or post your questions to be answered online via Extension’s ‘Ask an Expert’ widget.
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