We know the potential for a frost or freeze is coming sooner or later. When either of these weather conditions is forecast, we need to be prepared.
Plant coverings can protect against frost or cold. You can use sheets, quilts or frost/freeze cloth, and you should place them on the plants before the sun goes down. Other than frost/freeze cloth, covers must be removed during daylight. Frost/freeze cloth may remain in place for several days as air and light flow through the cloth. Don’t use plastic because it transfers the cold onto the plant. You can, however, put plastic on top of the sheet or quilt during windy freezes or on very cold nights. The covering you select must extend to the ground to capture heat from the soil and provide wind protection. Even though you have covered your plants, an additional source of heat may be needed. Christmas tree lights — not LED, because they do not provide heat — or a light bulb may provide enough heat to protect your plant from freezing.
Covering tropical plants in your landscape and those not hardy in your zone may help those plants survive cold weather. If you can’t live without tropical plants, you can move them from your landscape to your porch, lanai or garage. Your garage may well be 10-plus degrees warmer than the outside temperature and is an option for plant storage during freezing temperatures. Container plants can be covered to the ground or grouped together and covered.
Don’t encourage new plant growth by pruning or fertilizing because the plant will be more prone to cold damage. There are two options on pruning. The first is to delay pruning post-freeze until you see new growth and after the risk of a future freeze passes. Then prune beyond the point of black or brown stem coloration. The damaged plant material insulates and protects the live parts of the plant. The second option is to prune all dead plant material and freeze damage after the freeze. This makes it easier to cover and protect the plant if a freeze occurs before spring.
Healthy plants are less prone to cold damage and more resistant to insect damage or disease. Slightly moisten the soil before a freeze or near-freeze because moist soil releases more heat than dry soil. Hand watering the ground beneath the plant helps. Maintain a three-inch layer of mulch after it settles. Mulch helps regulate the soil temperature and protects the plant roots.
After a freeze you should check to determine if your plant needs water. Applying water to the soil will provide both a thaw and water for your plant. Most perennials are root hardy. While the foliage will die back to the ground, new growth will appear in the spring. Be patient because it can take several months before shoots are visible above the ground.