Wait to prune cold damaged plants
Coast Gardener Newspaper and Web Column - January 19, 2002
The recent freezing temperatures have caused quite a stir among gardeners. I have seen many subtropical and tropical plants damaged as a result of the cold weather. However, it is not uncommon to lose plant material from time to time. Even broadleaf evergreens such as azaleas and pittosporums suffer from freeze damage along the Coast.
Perhaps one of the most commonly injured plants is the sago palm. Ironically, this palm can tolerate a wide range of conditions, but foliage injury occurs quite often at low temperatures. For those of you who are unfamiliar with this plant, it is not a true palm. Its thick trunk and feather-like leaves do give the appearance of a palm; nonetheless, it is related to the ginkgo and pine trees. Furthermore, its origin dates back to prehistoric times. Its dark green leaves, called fronds, can reach lengths of three feet. Sagos are slow growing and recover slowly from injury. They do fit nicely into tropical landscapes and are used successfully as striking focal points.
The most obvious damage to sagos is the yellow or brown foliage that results from cold damage. I've checked a few in the area and all should recover. Only time will tell. They may not look very pleasing until plenty of new growth has had time to mask some of the damaged foliage.
Many gardeners are anxious about pruning right now. What is the best advice I can give? Try and hold off until new growth appears. Sometimes cold damage continues to show up into the spring season. The full extent of the damage may not be completely visible at this time. In addition, you could even remove too much live wood. Dead, unsightly leaves can be removed, but they could offer some protection should cold weather return later this winter.
Freeze injury may occur in different areas. Roots can be injured, especially if conditions are dry. Cold damage associated with the roots may not be visible until later in the season when the plant appears stressed. Moist soils allow for an insulation barrier for the roots and also allow water to continue to flow freely within the plant. Plants must have water even in cold weather. Cold, dry weather harms plants quickly. This damage is commonly called "wind burn."
The leaves and stems of plants sometimes are damaged when ice forms inside plant cells. They can, however, survive freezes that result in ice formation between the cells. Sometimes only the leaf edges, or margins, are damaged and turn brown. Severe cold damage causes entire leaves to change color and die.
As with your lawn and vegetables, I recommend a soil test for ornamentals and fruit and nut trees at least once every three years. If you do not have a soil test performed, consider fertilizing cold damaged plants at the rate of 1/2 to one pound of complete, mixed fertilizer every 100 square feet. Fertilize only after growth begins. Repeat every six weeks or so until August. Don't fertilize plants after this date. It could be harmful to the plants should we receive an early cold snap next fall.
As you begin to think about this year's garden, remember those plants that suffered through our winter's chill. You might consider other plants next time that are more tolerable of our conditions if covering, uncovering, and hauling plants in and out of the house is not your idea of fun.
These archived gardening columns were written by Chance McDavid, former Harrison County Extension Agent.