Growings On: Christmas freeze?

Were your evergreen trees or shrubs damaged by the freeze we had at Christmas? Young trees or those recently transplanted would have been especially susceptible. Both narrow- and broad-leafed evergreens — pines, junipers, Leyland cypress, arborvitae, azaleas, rhododendrons, hollies, boxwoods, nandina and photinia — are subject to injury from severe cold.

All evergreens retain foliage throughout winter and, as a result, they continue to undergo transpiration (water loss from the leaves) though it is slower when compared to the warmer growing season. When low soil moisture combines with freezing temperatures and strong winds, the roots are unable to replace any moisture lost during transpiration. This is what causes what we call winter burn, which appears as browned foliage and/or blooms. This burned appearance can sometimes be confused with disease symptoms, or you may even think it is dying.

Winter injury can also damage flower blooms, especially if they try to bloom early, as often happens when we have early warm weather that is followed by a cold snap. If you see the entire plant affected then the damage is probably due to an environmental cause rather than plant disease.

Regardless of the type of cold damage, it is best to wait until spring, when everything is leafed out, before pruning any damaged limbs or twigs so you don’t get freeze damage on the new growth that results.

You should prune dead twigs and branches back to about an inch from still-living tissue or to the next live branch. Depending on the extent of the damage, the plant will probably drop the dead or damaged leaves on its own and then produce new ones. You will also need to fertilize as soon as spring begins and water your plants well throughout the growing season in order to help them recover. Plants damaged by cold injury will be more susceptible to drought stress in summer so will need some extra loving care through the year.

For additional information, see https://tinyurl.com/4nf6w6ub. If you have any questions, feel free to contact Brenda Jackson at Murray County Extension at (706) 695-3031 or email bljack@uga.edu.