Dealing with Cold-Damaged Landscape Plants
Are the plants in your landscape looking brown and dead after the recent hard freezes? If so, you may be wondering what to do about them. The first thing to do is nothing! We are likely to have additional cold weather events before spring arrives. Leaving the dead foliage on plants can provide some protection against direct cold and sunburn.
This freeze was unusual in that the temperatures dropped around 50° F in a 12-hour span. Some flowering shrubs in the southern part of the state were even blooming.
Many plants have significant woody tissue damage. This woody tissue is where plants store food to be used for replacing the freeze burned leaves that will eventually fall from the plant. These fallen leaves can add some insulative protection to the roots if any further cold weather occurs. They will eventually decay and release their nutrients to the plant roots.
Pruning now will likely damage the healthy tissue that the plants will need to heal. Secondary infections may also occur. Wait until it is clear what tissue has died and until further freezes are not expected. This may be a month or more in most parts of the state. The only exception would be if the frozen tissue gets a wet decay (breakdown) or has an odor. Then it is good to prune the area out, bag, and destroy the affected leaves.
Use a sharp blade to lightly skin the bark to reveal the wood beneath. Start at a branch tip and observe the color under the skinned area. Damaged wood should be brown. Work your way down until the skinned area becomes green. This indicates healthy tissue. Prune off the tissue above the green area.
For more information, please see MSU Extension publication ‘IS 1663 The Plant Doctor – Cold Injury’ at www.extension.msstate.edu/publications. For Palms refer to publication ‘P 2828 Cold Injury to Palms’.
By Jeff Wilson, Modified from previous article by Alan Henn and Clarissa Balbalian.