Some vegetables will continue growing through all but the coldest part of winter. When deciding which vegetables grow best in the winter, take into account your USDA hardiness zone. You will need to construct some type of cold frame, which is a small, boxlike structure made of wood, plastic, glass or straw bales, to protect your vegetables from winter weather conditions. Once your cold frame is in place, you are ready to grow vegetables year-round.
When contemplating which vegetables grow best in the winter, add lettuce to the list. For the best results, grow lettuce in a cold frame. Suspend row cover, a lightweight polyester or polyethylene fabric, above the lettuce plants to provide an additional layer of protection from the cold. Use a lightweight metal frame such as a tomato cage to keep the row cover from touching the lettuce.
Direct seed lettuce in late summer so it has warmth to germinate and time to grow into a full-size plant. An alternative to seed is young lettuce plants. Simply transplant these into the cold frame in late summer to give the plants time to establish themselves before cold weather sets in.
Direct seed carrots in the garden in late summer as well. Seed that does not germinate at that time may germinate in late winter as the temperatures begin to rise. The same holds true for lettuce seed. Finding out what seeds will germinate in cold weather conditions will help you determine which vegetables grow best in the winter.
Over-winter carrots in the garden in a cold frame. The use of a row cover is suggested. Another way to over-winter carrots in the garden is to cover them with a thick layer of straw. The straw will keep the ground warm. When you wish to harvest carrots, simply pull the straw back and dig them up.
If you live in USDA hardiness zones 5 and up, plant seed potatoes in late November through late December. Be sure the seed potatoes are pre-sprouted, which means green growth will be coming from the potato.
Dig a hole 12 inches deep. Do this before the ground freezes. When you are ready to plant your potatoes, add 4 inches of dry grass clippings, compost or straw. Lay the sprouted potatoes on top. Cover the potatoes with enough of the same material to cover all the new green growth. Add enough soil or compost to cover the grass clippings or straw. Cover this with a cold frame. By May or June of the following year, the potatoes will be ready to harvest.