Although winter injury does not occur as regularly in Georgia as in colder parts of the country, we do see a fair amount of cold damage to plants, especially young, succulent tissues or newly transplanted plants. Both narrow- and broad-leafed evergreens, such as pines, junipers, Leyland cypress, arborvitae, azaleas, rhododendrons, hollies, boxwoods, nandinas, and photinias, are also subject to winter injury and desiccation. Winter burn occurs when there is low soil moisture, freezing temperatures, and/or strong blowing winds.
Because evergreens retain foliage throughout the winter, they are continually transpiring water, although to a lesser extent than in warmer weather. If there is low soil moisture or temperatures below freezing along with heavy winds, the roots cannot readily replace the water that is lost through transpiration. This, in turn, causes winter burn with symptoms expressed as browned or bleached foliage and new blooms (see below). This can sometimes be confused with plant disease symptoms and therefore proper diagnosis is important for implementation of management strategies.
Winter injury is expressed as browned foliage as shown below on the two evergreens.
Winter injury can also damage flower blooms as shown on the azalea below. If an entire plant is affected (all the blooms), then the damage is likely due to environmental causes or an ‘event’ rather than plant disease organisms.
The new foliage on this oak tree was damaged by a late spring freeze.
Regardless of the type of winter injury seen (discolored, burned evergreen needles or leaves, dead branch tips and branches, or necrotic blooms), often it is beneficial to wait until spring to assess the extent of the damage.
Prune dead twigs and branches back to about an inch from live tissue or to the branch collar of the next live branch. Depending on the extent of the damage, the plant will likely drop the dead/damaged leaves and produce new green foliage. Removing the dead and damaged leaves and blooms will help stimulate new plant growth and reduce the chance of infection from secondary plant disease organisms.
Once the weather warms up, it is important to fertilize the injured plants early and irrigate the plants well throughout the season, if possible. Many times, plants injured by cold temperatures are more susceptible to drought stress later in the summer.
Weed Pro would like to Thank UGA for this Great Info!!