Many of us know what to do to protect our landscape plants before a cold event by the instructions you get from the Certified Meteorologists at your local television station. Usually we will water the plants well, both in-ground plants and containerized plants to get a little heat around the roots before the cold weather event arrives. Then we cover cold sensitive plants with cloth covers all the way down to the ground to try to trap some of that heat that is leaving the soil. But now that the cold event is over, do you know what to do?
Don’t be in a hurry to prune out this early damage. Better yet, take a survey of your yard and identify those plants that may not have been the right plant for the right place (landscaping principle #1 for the Florida-Friendly Landscape™). Central Florida is not a tropical environment. Tropical plants, including tropical fruit trees and warm season vegetables, have a real tough time when the temperatures drop into the 40s (degrees F.). The sudden drop in temperature will create a situation where they may become more susceptible to diseases and insect pests. So make a list of the most damaged plants in the landscape for now and perhaps when you think about it, these plants may not be the best ones to replace next spring.
Some plants in the landscape are sensitive to environmental changes and respond quickly to a change in temperature (both high and low temperatures), changes in rainfall (too much or too little), and changes in sunlight (too bright or too cloudy) by dropping their leaves or clinging onto many leaves that suddenly changed to yellow. Hibiscus, gardenia and ficus are usually in this group.
When the leaves drop suddenly, there isn’t much you can to do at this time of year. Pruning may encourage sudden development of lateral buds, which will be even more sensitive and cause more damage to that plant with the next sudden drop in temperature. Maybe hanging a few holiday ornaments on the plant will improve its appearance until spring when the warming temperatures will stimulate new growth and show you where pruning should be done.
Those few plants that developed many yellowing leaves can look green again by simply removing those annoying yellow leaves. Now, with only green leaves left on those plants, things will look normal again until the next sudden drop in temperature.
Now would be a good time to inventory your plants that show no stress as a result of the sudden cold spell. Those may be the plants you will want to add more of to the landscape next spring and remove some of those very cold sensitive tropicals. Even native plants may be damaged by severe cold. They too have a hardiness zone limitation. Native plants that flourish in South Florida may not survive the winter in North Florida.
Be sure plants receive sufficient water after a cold weather event, especially if plants are in containers. Foliage could be losing water on sunny days through transpiration after a cold weather event. Apply water to warm up the soil.
It is often difficult to determine how far the damage extends in cold damaged plants. If the cambium layer, just under the bark (scrap with a fingernail or pocket knife), is still green then the plant is still alive.
Dead, unsightly leaves may be removed when they turn brown if desired, but complete damage may not be known until spring. Once new growth begins, start pruning below the damaged area. Prune off the brown stems above the new, green buds in early February.
Florida homeowners may enjoy a vast array of plant materials and often desire a tropical or semitropical appearance to their landscapes. Cold sensitive plants are often planted past their northern limit in Florida. A mixture of both tropical and subtropical plants should be considered for use in landscapes where cold damage may occur so that the landscape will not appear totally devastated. The Florida homeowner should be prepared to protect or replace the cold damaged plants when necessary.
Now you know how to care for your cold damaged plants and when to prune them to prevent damage from the next cold weather event.