Cactus Village Community

FROSTY NIGHTS ARE POSSIBLE

Jul 27, 2003

Okay, we never have to shovel snow here, but it does get cold in the winter?—cold enough for Jack Frost to make unwanted appearances. According to the University of Arizona College of Agriculture Extension Center in Maricopa County, the average first frost date in Phoenix is December 12; the last average frost date is February 7, which means we?’re about in the middle of a two-month period for potential frost damage to our plants.

Here are the Extension Center?’s suggestions for dealing with the occasional nippy night. When the temperature drops, cover plants completely with cloth or paper, but not plastic, from the top of the plant to the ground, without any openings for heat to escape. Coverings should be removed every morning when the temperature underneath warms to 50 degrees unless special commercially-made frost cloths have been used. Many of these can be left in place for extended periods of time without damaging the plant.

Young citrus are frequently protected by loosely wrapping the trunks with multiple layers of cloth or weather-resistant paper from the ground to the level of the lower branches, and can be left on through mid-February. A trickle of running water to the ground at the tree?’s base for up to three nights (not longer, as the risks could at that point outweigh the benefits) may offer additional protection, as the water in its cooling process will release energy in the form of heat.

Methods NOT recommended are fires which send hot air up above the plants, sucking cold air from nearby areas (and risking netting you a fine from the County for polluting the air?—see the no-burn caution); mulch, as it prevents the warming of soil; chemicals; and smudge pots.

And a final note about frost damage, should it occur. Don?’t be too eager to trim away the unsightly areas. Pruning can, in fact, stimulate new growth that could be vulnerable to further or late frosts. Be patient! The damage may not ultimately be as bad as it initially seems, and new growth may occur in tissue you thought was dead. When new growth starts in the spring, prune away! . . . ☻