While an early freeze can be bad for plants, warm temperatures in December are mostly harmless, experts say.

Bob Stirling, owner of Stirling Landscape and Nursery in Center Township, said that cool, moist weather is mainly a positive for trees and shrubs.

“There shouldn’t be any damage. It’s good for plants to go into winter with wet feet,” he said.

Stirling said below-zero temperatures can damage plants, but mild weather is fine.

“It’s purely positive for plants. It’s an extended cool, but damp time, and there’s no insect activity or disease activity this time of year either,” he said.

Dave Himes, owner of Green Valley Nursery Center in West Sunbury, said some of the more delicate flowering plants can be affected by unseasonably warm weather in December.

Rhododendrons, azaleas, roses and other plants sometimes will start to grow buds or even bloom, and if that happens, they may not bloom in the spring.

“It’s terrible because the plant has already started to grow again,” Himes said.

“When that happens, any new growth in the spring will be slow. The blooms will get frozen out now.”

Himes said he has gotten some calls recently from people who have seen buds on bushes in their yards, but there isn’t anything they can do about it.

“Do not cover your plant; it will make it grow earlier in the season than it should, almost like a greenhouse effect. There’s nothing they can do. Let mother nature take it’s course,” he said.

Chuck Smith, a master gardener in Portersville, said most plants that people have growing in Western Pennsylvania won’t be too affected by a couple of warm days.

Many plants would need two or three weeks of sustained warmer temperatures before they react like it were springtime.

“Trees and bushes are relatively slow, they don’t react overnight,” he said.

Though there was a quarter inch of snow and freezing temperatures over the weekend, the forecast calls for unseasonably warm weather again this week.

The National Weather Service predicts a high near 60 Thursday, with other highs expected in the 50s.