By Sharon Omahen
University of Georgia
Georgians are accustomed to unpredictable winter weather. But landscape plants don't understand. Many have adjusted to the recent warm spell and will suffer when temperatures drop again.
"We know to put on a winter coat when it gets cold, take it off when it gets warm and put it back on again when it turns cold again," said Marco Fonseca, a University of Georgia horticulturist.
Landscape plants don't have this luxury.
To late to turn back
"Once they begin to change from their winter state to their spring state," he said,"there's no turning back."
Landscape plants prepare themselves for winter temperatures. Many grow "fuzzy insulating exterior layers" for protection, he said.
"The plants also reduce the amount of water they absorb and create their own antifreeze condition," he said.
When winter temperatures rise, landscape plants think spring has arrived. The soil warms and the plants pump water into their roots and tissues.
When this happens, outdoor plants start growing, and flowering plants begin to produce buds, Fonseca said.
"Right now, these buds are swelling and preparing to open," he said.
When temperatures drop, these plants will be much more susceptible to freeze damage because of the changes they've made.
Soil moisture has risen during the warm spell, too, he said. When freezing temperatures return, the soil moisture will cause plant roots to freeze.
Mulch and cover
So what's a home landscaper to do?
Fonseca and other UGA horticulturists recommend adding extra layers of mulch to insulate outdoor plants' roots. If spring bulbs have begun to emerge, cover them with a layer of mulch until the freeze passes.
"It's not an attractive solution, but you can protect your larger flowering shrubs by covering them with cloth at night," Fonseca said.
Cover any landscape plants that have started producing buds, like forsythias and azaleas, he said.
"Basically, that's all you can do," he said. "Once the plants begin to push and grow, they can't turn back when Mother Nature changes course."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)