By Randall Mallette, LSU AgCenter County Agent
With freezing temperatures forecasted in the coming days, it is time to start thinking about protecting our plants from cold damage. Freezing temperatures causes the water in plant cells to freeze, permanently that area of the plant. Depending on the severity of the freeze, plants may have damage to just a few leaves, or the entire plant may be affected. Container plants are particularly susceptible to freeze damage because their roots are not insulated by the ground.
Covering damage prone plants is a common method of protecting from frost damage. Coverings increase the temperature around the plant and block cold, dry winds that are often associated with cold weather events. Sheets, blankets, or frost coverings are preferred. However, if a heavy blanket is being used, it is advised to have it supported instead of resting on the plant. If ice or snow accumulates on the covering, the additional weight can break plant stems. Some simple stakes that are slightly taller than the plant work just fine for supporting the covering and keeping it off the plant. If using plastic, be sure to keep the plastic off the plant because leaves can freeze to the plastic. To get the most benefit out of covering a plant, make sure that the covering reaches all the way to the ground and is weighted down. This allows heat that is released from the soil to warm the air under the covering.
Another recommended practice prior to a freeze is to thoroughly water plants. Freezes often include cold dry winds which dry out plants, causing damage. Having plenty of water in the soil available to the roots allows plants stay hydrated throughout the freeze.
Not only are Christmas lights festive, they can also help mitigate freeze damage to plants, especially when combined with a covering. The small lights put off heat. Under a covering, the slight increase in temperature can be more than enough to keep your plants comfortable, however, it is important to keep plastic coverings from resting against the lights.
For container plants, it is best to move them indoors or to a covered area. If that is not possible, group them together and put a blanket or other covering over them, making sure it is weighted down and covering the container. Since containers dry out quickly, it is recommended to water them thoroughly.
Fall gardens can typically handle our winter temperatures, but row covers are available in the event that temperatures get extreme. Again, a deep watering is recommended prior to freezing. If using a row cover, make sure to keep it out of contact with leaves if possible.