The cold months of December through March provide a perfect opportunity for building cloches,
Fall and winter vegetables can be started by seed from late August to mid-September, then transplanted into the garden later. Seeds should be started indoors where temperatures are cooler, then the seedlings slowly transitioned outside once temperatures cool down in early October.
Transplants of warm season vegetables such as tomatoes and peppers or seeds of crops like green beans, should not be planted until the danger of frost has passed as they do not tolerate freezing temperatures (below 32°F) and may see damage when exposed to frost (wich can occur at temperatures below 36°F).
These cold-weather champs are kale, spinach and collards. Other hardy vegetables include broccoli, Brussels sprouts, English peas, kohlrabi and leeks. Hardy root crops are radishes and turnip, which also yields some greens from the tops.
While many crops won't grow during winter's coldest temperatures (say goodbye to melons, tomatoes, squash, and peppers, for example), many vegetables will tolerate and even thrive on the cooler temperatures that come with fall and winter. The main limiting factor at this time of year is sunlight.
Grow winter crops in a cold frame or plastic tunnel
Plant vegetables for winter harvest in a cold frame or plastic hoop tunnel or have portable hoop tunnels or cold frames read to set over plants when a frost or freeze threatens. A cold frame or a plastic hoop tunnel will protect vegetables from cold temperatures.
Carrots, onions, and potatoes are perhaps the most popular among this special group that also includes beets, celery root, kohlrabi, parsnips, radishes, rutabagas, and turnips. During the colder months, these veggies find their way into the spotlight and onto the plates of healthy eaters—and all for good reason.
Tomatoes are a warm-season crop that dies back when cold temperatures threaten. This usually means no home-grown tomatoes in winter, unless you have a greenhouse. You can, however, grow tomatoes indoors, but they are usually smaller and produce less prolifically than their summer cousins.
According to Myers, the hardiest vegetables that can withstand heavy frost of air temperatures below 28 include spinach, Walla Walla sweet onion, garlic, leeks, rhubarb, rutabaga, broccoli, kohlrabi, kale, cabbage, chicory, Brussels sprouts, corn salad, arugula, fava beans, radish, mustard, Austrian winter pea and ...
Most cucumber varieties are extremely tender and cold sensitive. Generally they will be harmed or killed by frost. Many varieties grow slowly or not at all at temperatures below 55°F. Plants may become stressed and fruit quality diminish during periods of cool weather below 50°F.
Seedlings, with their tender new leaves, often give up the ghost when temperatures dip to 32-33°F. Tropical plants have differing low-temperature thresholds. Some keel over when temps fall to 40°F; others crumble at 35°F. Other plants are just hardy by nature and can withstand temperatures as low as 18-20°F.
Ideal temperature range for growth and fruiting is about 65° to 75°F. Zucchini withstands temperatures up to 100°F, but growth and fruiting may be diminished at temperatures above 85°F, and flowers may drop at high temperatures. Most varieties grow slowly or not at all at temperatures below 60°F.
Tips for Winter Growing
Use container gardens! Container gardens, because of the 'raised bed,' means warmer soil and more sun. These two things are the most important part of having a successful winter garden, so containers are a reliable option for cold weather growing. Create a mini-greenhouse effect with cloches.
Spring is usually the best time to start a new garden but plants may be added in spring or autumn, depending on the type of plant. Plants that thrive in the cold, like pansies and kale, can be planted in autumn or winter. Annuals and tomatoes should be planted when the weather warms up and after the last frost date.
You can plant or harvest something from your garden almost all year. The two major planting periods, however, are spring (March to May) and fall (mid-July to September). The spring plantings are harvested in June and July, while the fall plantings are harvested from October to December.
You can sow seeds for winter vegetable crops, like salad greens, radishes, carrots, onions, Swiss chard, English peas and kale. Look for transplants of other cool-season vegetables, including Brussels sprouts, broccoli and cauliflower. Herb transplants also appear in garden centers during winter.
Contrary to popular belief, there are quite a few fruits that actually thrive in cold weather, like apricots, pears, and Mandarin oranges. If you're looking for delicious ideas for fruits that grow in winter, your options will depend on your location's USDA Plant Hardiness Zone.
Absolutely. But they do have some specific requirements. The main downside to this overwintering method is that indoor tomato plants need a lot of sunlight. Yes, you can put the pots on a bright windowsill, but even in the brightest window, in most cases they will survive the winter with just a few scraggly leaves.
Favorites like tomatoes, beans and cucumbers complete their entire life cycle in a single growing season and are killed by the first hard frost. There are few true perennial vegetable plants that come back year after year.
Another temperature to keep in mind: tomato plants will not survive in temperatures below 35 degrees Fahrenheit, and will not thrive at temperatures below 50 degrees. Gardeners can use a frost date calendar to note their region's average dates of last frost in spring and first frost in fall.
Some plants (like carrots, kale, spinach, and brussels sprouts) have the ability to convert some of their starch stores into sugar. They do this to keep the water in their cells from freezing. So the adaptation that keeps them from dying in the cold also makes them sweet and delicious!
During the winter months, something amazing happens to root crops like beets, carrots, and turnips if you leave them in the ground. As you overwinter these crops, the cold temperatures cause a phenomenon known as chill-sweetening, wherein the plants convert starches into sugars.