Chances are that you don’t have much to harvest from your garden these days, but if you do, then there’s a good chance it’s at least somewhat green and leafy. Lettuce, bok choy, spinach, turnip greens, collards, and swiss chard are among the hearty plants that are able to thrive in cooler temperatures. If your local temperatures have been too cold even for those crops, then head to a grocery store and keep your eyes open for special deals and seasonal sales in the produce department. Keep in mind however that lettuce has such a high water content and such thin tissue that it does not tend to preserve well using any method.
As mentioned in the recent New Year’s posting, Spinach and Other Greens can be canned, using a pressure canner. You might be amazed at the quantity you can fit in each jar once the tender leaves have wilted from being steamed – a canner load of 9 pints requires about 18 pounds of greens, and a canner load of 7 quarts holds an impressive average of 28 pounds! Note: These “other greens” should be greens with a similar texture to spinach, and not very hard, firm leaves such as cabbage.
Freezing greens is an option, but is recommended only for use as a cooked vegetable. This is for the sake of quality — their cells are full of water and those thin cell walls will burst when that water freezes and expands. So, rather than making a salad with frozen greens, try using them in casseroles, lasagna, soups, sauces and dips. Also, keep in in mind that leafy greens will heat more evenly if thawed before cooking. The water blanching time for most Greens, including Spinach, is 2 minutes, but water blanch collards for 1 additional minute (blanch time: 3 minutes) and Cabbage for 30 seconds less (blanch time: 1½ minutes). Blanching is important to slow or stop destructive enzyme action, clean surfaces, brighten color, help retain vitamins, and make the vegetables easier to pack into jars. Specific directions for water blanching are available here.
Perhaps the least common method of preserving greens is to dry them. However, dehydrating can be a useful method for use in baked goods, soups, and casseroles. Dried greens may even be ground into flour to sneak some extra nutrients into breads, pancakes, and cookies. As with freezing, blanching is required. Cabbage can be water blanched for 1½ to 2 minutes or steam blanched for 2½ to 3 minutes or until wilted. Other greens can be water blanched for 1½ minutes or steam blanched for 2 to 2½ minutes or until wilted. Read this publication from the University of Georgia for more information about Drying Fruits and Vegetables.