How to Use a Garden Frost Cloth

Even a light frost can damage many warm-season plants. Whether you need to protect young plants from a late season spring frost or you want to extend the growing season past the first frost in fall, most plants require frost protection to prevent damage or death. Made from a breathable fabric, a frost cloth prevents frost from settling on plants. These cloths also help retain warmer temperatures underneath their coverings by providing a layer of insulation between the plants and the outdoor air. When used properly, a frost cloth protects a plant down to temperatures between 20 and 30 degrees Fahrenheit.

Stakes

Tomato cages

Rocks

Insert a stake on either side of the plant, using stakes that sit higher than the plant by 6 inches once they are installed. Place a tomato cage over smaller plants.

Cover the plants one to two hours before sunset on the evening of the predicted frost. Drape the cloth over the stakes or tomato cage, positioning the fabric so any excess pools on the ground around the plant. Foliage that touches the frost cloth can still suffer frost damage.

Anchor the bottom of the cloth with rocks or a small pile of soil to help retain more warmth underneath it.

Remove the cloth in the morning once outdoor temperatures are above freezing and the temperature under the cloth is over 50 degrees F. In spring, heat trapped under the cloth can cook plants, while in fall and winter the heat can cause plants to break dormancy prematurely.

You can substitute blankets and sheets for purchased frost cloths, but keep in mind that these items do not breathe as well and so may cause damage to plants if they are used over an extended period.

Frost cloths made for trees and shrubs can be draped over foliage without the use of a frame, if necessary.