Can lettuce be grown in cold weather?

Growing lettuce in cold weather begins with frost-tolerant varieties. Lamb's lettuce and winter purslane will survive to about -7°C (19°F) if covered. I gather fresh greens through the snow by using these methods. Begin with a few cold-hardy varieties that are suitable for your zone.

Prepare your cold frames at a slope of about 30° due south, insulating the sides with bales of straw. Cover the top with double thicknesses of plastic or polycarbonate, and ventilate at the top if the outside air temperature is above approximately 4°C (39°F); otherwise, keep them closed. My cold frames will produce greens when the air temperature falls to about -10°C (14°F).

Time plantings for winter harvests. Sow 8-10 weeks before first frost. Choose slower-growing varieties. Space plants 15 cm (6 inches) apart. Water the ground before it freezes so they will be established before the deep cold sets in.

Dark mulch is an effective way to control soil temperature. Black or dark colored plastic is effective at absorbing sunlight. Warm water is used to thaw freezing weather midday watering. Fertilizing should not occur when temperatures are below freezing. These methods allow plant roots to remain active and growing during cold periods.

Cut the outer leaves cautiously and leave the remaining leaves to regrow. Wash cut lettuce quickly in cold water. Store in the 0-2 °C (32- 36°F) temperature range. Sweetness is an advantage of cold-grown lettuce. This is the result of the natural antifreeze components found in cold-grown lettuce.

Read the full article: When to Harvest Lettuce for Best Results