March 11, 2022–5:18 p.m.
Keith D. Mickler
University of Georgia Extension | Floyd & Polk Counties
No doubt, plant damaging cold air will be arriving this weekend. Yes, damage is going to occur. Even though there’s not much we can do, there are a few things we can do so to reduce the damage. Remember I said reduce damage, not stop damage.
Here are a few things to consider that might help reduce damage and protect our plants.
First, let’s make sure the soil around the plants is moist, I said moist not sopping wet:
Watering plants before a freeze will help protect them. A moist soil will absorb more solar energy than a dry soil and will reradiate heat during the night. A moist soil can raise minimum night temperatures in the canopy of plants by as much as 2°F. However, prolonged waterlogged soil conditions will damage the root systems of most plants. Thank goodness, our soils are wet. No more water needed.
Second, cover your plants with sheets or plastic:
Covering tender plants left outdoors during the winter is not always effective or practical. However, it can help, but only if done right. Improper cold protection via covering can be worse than not covering the plants at all.
Temperatures are usually just a few degrees warmer under the covering, this is often enough to get a sensitive plant through a cold night. Coverings protect more from frost than from extreme cold. Covers that extend to the ground and are not in contact with plant foliage can lessen cold injury by reducing radiant heat loss from the plant and the ground. Foliage in contact with the cover will be injured because of heat transfer from the foliage to the colder cover. Some examples of coverings are cloth sheets, quilts or black plastic.
It’s absolutely necessary to remove covers the next day once temperature are above freezing, especially if it’s a sunny day so to vent out the heat we trapped under the cover. A light bulb under a cover is a simple method of providing heat to plants (well, if plugged in and turned on of course).
Covering with wheat or pine straw:
Wheat straw or pine straw can be scattered loosely over plants low to the ground and probably left during a cloudy cold day, but removed if the next day warms up. Wheat or pine straw can be removed with a leaf blower; however, it will create a big mess to clean up.
What to do after the freeze:
Plant water needs should be checked after a freeze. The foliage could be transpiring (losing water vapor) on a sunny day after a freeze while water in the soil remains frozen. Apply water to thaw the soil and provide available water to the plant.
Severe pruning should be delayed until new growth appears to ensure that live wood is not removed. Dead, unsightly leaves may be removed as soon as they turn brown after a freeze if you desire. New growth and young branch tips may be damaged while older wood is free of injury. Cold injured wood can be identified by examining the tissue layer just under the bark for black and/or brown discoloration.