Be prepared for the next cold snap

“Only two people predict the weather: newcomers and fools.” I was offered this stern advice years ago from a Florida native nurseryman. He instructed me that in Southwest Florida we are at risk of frost until the full moon in February.

We can prepare for the worst by doing the following things in our landscape.

1. Don’t prune shrubs too hard. If we remove a lot of branches now the plant will respond with new, tender growth that will be easily damaged by frost. Postpone major pruning until spring.

2. Water. Unseasonal warm days are depleting soil moisture. By applying about 1 inch of water per week, the soil will be warmer and help to radiate heat. Irrigate before a cold night.

3. Do not water during a frost/freeze event. If your irrigation goes off during a cold snap, and then cycles off, your plants will suffer more cold damage.

4. Citrus groves and strawberry growers will routinely “ice” their crops on cold nights. But one requirement of this method is the water must run continuously until the air temperature is near 40. This is not practical for our typical urban garden. It can produce flooding and fungus.

5. Frost fabric will gain about 4 to 5 degrees of warmth. It will help trap radiant heat from the soil and prevent the cold from settling on the plant’s leaves. For best effect, “tent” the fabric slightly above the plants so it is not touching the leaves. And, like a tent, you should peg the fabric edges to the ground to prevent cold air from entering.

6. Fungicide is a peculiar preparation that has legitimate effect. By spraying trees and shrubs with copper fungicide, your plants could suffer less cold damage. There is a certain, common disease that is found on some plants in small amounts. This “ice-nucleating” bacterium is shaped like the center of a snow flake and will hasten the formation of ice crystals. By treating plants with liquid copper, you will discourage some cold damage.

— Bob Cook, a Florida nursery grower, is with the Royal Palm Chapter, FNGLA.