Lettuce grows well in cool weather, but the vegetable can only tolerate a light frost. A temperature range between 55 and 60 degrees Fahrenheit works best. When the temperature drops below 28 degrees Fahrenheit, the lettuce needs protection from the frost. A heavy frost can damage or kill the lettuce, wiping out the crops that you worked hard to grow. When you anticipate a frost in your area, cover the lettuce to err on the side of caution.
Things You'll Need
- Floating row covers
- Burlap sacks
- Plastic water jugs
Place straw, hay, pine needles or other mulch material around lettuce plants if you have a small garden. Place the material on the ground around the plants to help keep the ground warm.
Place floating row covers, sheets, burlap sacks or plastic water jugs over lettuce in larger gardens.
Water the soil 1 or 2 days before the expected frost. Moist soil holds more heat than dry soil. Avoid saturating the soil when the temperatures are low, because it can injure the plants. Water lightly in the evening before the temperatures drop.
Harvest the lettuce if you cannot cover the vegetables. Pick as much of the lettuce as possible and store the heads in the crisper drawer in the refrigerator.
Tips & Warnings
- Remove the frost covers in the morning when the temperature rises to allow the lettuce to receive adequate sunlight.
- Purdue University Extension; Gardeners Should Prepare to Avoid Frost; B. Rosie Lerner; September 2004
- Danny Lipford; How to Protect Your Garden From Frost and Freeze; Julie Day
- Vegetable Gardener; Frost and the Fall Garden; Ruth Dobsevage; September 21, 2009
- National Gardening Association: Growing Head Lettuce
- Cornell University Cooperative Extension; Understanding Frost; Eric de Long Chemung; September 2001
- Photo Credit Thinkstock/Comstock/Getty Images