Palms may survive, and even thrive, for years in climates cooler than those to which they are native. However, these plants eventually will experience temperatures cold enough to cause injury. Here in Crestview, that happened in January.
When cold damage is severe, plant tissues are destroyed and water uptake into the plant may be reduced for years. Often, only the protected bud will remain alive; in that case, palms can still be saved.
A common problem associated with freezes is that the spear leaf's freeze-killed lower portion is degraded by secondary fungi and bacteria ever present in our natural environment. Palm owners considering trimming damaged leaves following cold weather should avoid the temptation until the danger of additional freezes passes. Even dead leaves insulate the critical bud.
As weather warms, you should remove dead fronds surrounding the bud to let the spear dry out. Drenching the bud area with a copper fungicide will reduce secondary microbes. Copper fungicides, unlike other fungicides, are active against bacteria and fungi; do not use a copper nutrient spray. Be sure to repeat applications as palm leaves develop, and delay fertilizer application until you notice new fronds. The best analysis for palms is 8-2-12 plus 4Mg.
Cold-damaged palms can still show symptoms six months to a year following a freeze. New leaves in the spring may appear misshapen.
Usually, the palm will outgrow the damage. However, the palm sometimes loses its ability to take up water. If there is a sudden collapse of the fronds in the crown during the first hot days, the palm may die.
If that happens, nothing can save the palm.
Sheila Dunning is an agent at the University of Florida's Institute of Food and Agricultural Sciences Extension office in Crestview.
This article originally appeared on Crestview News Bulletin: THE EXTENSION CONNECTION: Here's how to treat cold-damaged palms