Warmer weather puts plants at risk for winter damage

Gardeners might want to pray for frost.

Although 60-degree springlike temperatures might be luring some gardeners outside, at least another month of cold is needed to keep plants safe, plant specialists say.

"Next week, if we don't get some cold weather, we're really having a problem," Jenny Addie, the nursery manager for Green Thumb West, said Tuesday.

Many plants, shrubs and trees are taking cues from the above-average January temperatures that spring is right around the corner and are beginning to come out of dormancy.

"Right now we're about three or four weeks ahead on a lot of plants," said Charles Phillips, Columbia County's Cooperative Extension agent, adding that the pre-emergence from dormancy is mainly affecting spring-blooming plants. "I've already seen daffodils in full bloom. We normally don't see those until toward the end of February. ... A bunch of the trees like red maples are already flowering and releasing buds."

This January has been one of the warmest since 1990, with average temperatures hovering just above 51 degrees. The average January temperature is normally in the mid-40s, Georgia State climatologist Dr. David Stooksbury said.

If no cold weather arrives before spring kicks in, all of the early-blooming plants will continue to bloom and not be in bloom at their normal flowering times, Phillips said.

Too much warm January weather causes many plants to break dormancy, making them much more susceptible to damage from cold temperatures Stooksbury expects to arrive soon.

"I do expect to see more of a normal trend, which for east central Georgia, we're talking about lows in the mid-30s and highs in the mid-50s," Stooksbury said, adding that this winter has been marked by temperature and other climatological swings. "... I expect we're going to be much more near normal. ... If we don't turn cold, I'm afraid we're not going to have a pretty spring."

February could even hold a bout of frigid cold, which Stooksbury said he expects.

Phillips said the real worry for gardeners is that with plants breaking out of dormancy, their protective state to survive the winter months, they will not be safe if the cold weather does arrive.

"The plants are releasing dormancy, so they are not hardened off," Phillips said. "Then we come in here in February and March, which is when we get some of our coldest weather, and the plants are thinking it is spring and are turning green. Then we are going to see a lot of winter damage."

Hydration is the key to plant survival when the cold arrives, Addie said.

"Watering is the best thing,'' she said, adding that plants need water in the winter, too, but for different reasons. "If it is dry cold and the plant doesn't have enough hydration in it, it will cause way more damage than if the roots are wet."

Cold and wind tend to pull moisture out of the plants and soil, Phillips said.

"The main thing is it is warm and everything is signaling (plants) to start growing," Phillips said. "(They) start releasing out of dormancy and we get this sudden drop in temperatures and the plants get winter damaged."

Winter damage can range from burned edges of blooms that were in bud form when the cold hit, to cracking and splitting stems, usually at the soil level.

Other than keeping plants well hydrated, insulating plants also helps keep them from winter damage. A good layer of winter mulch around the base protects by holding in heat and moisture.

"If we are getting a cold spell coming in, we soak water everything, then we purposely ice over with a layer of water just to insulate the plants," Addie said.

For those who are uncomfortable icing plants, sheets, towels or landscape fabric will work for nights and should be removed each morning. Plastic should not be used to cover plants.

"Pull the covers off during the day," Phillips said. "If not, it will build up too much heat under there. Building up heat will cause the plant to go ahead and break dormancy that much faster."

Addie said plastic nursery pots covered in pine straw also can protect plants overnight but must be removed in the morning.