Winter protection of ornamental plants

Cold damage to ornamental plants can be a problem during the winter in the Georgia landscape. This is true whether you live in the upper elevations of the mountains or in the most southern regions of the state. Regardless of where you live there are some practices you can do to maximize the chances that your prized landscape plants will make it through the winter unharmed.

During the summer months ornamental plants are actively growing and would be severely injured by even the slightest frost. Therefore during the late summer and early fall the plants must prepare themselves for winter through a process called acclimation. This process is initiated by the cooler temperatures and shorter day-lengths that naturally occur at this time of the year.

It is imperative for cold acclimation to occur in a timely fashion. If it occurs too early the growing season of the plants will be shortened, if too late they will be injured or killed by early frosts. Several factors including local weather conditions, plant selection, and how you treat the plants during the growing season can affect the timing and extent of cold acclimation of landscape plants.

Types of Damage and Conditions

Cold injury can occur on all parts of the plant including fruit, stems, leaves, trunk and roots. Typically, homeowners notice the cold damage first on the leaves and stems as ice forms within the plant=s cells. As plant tissue dies the leaves or stems become brownishblack and mushy. Cold hardy plants that are acclimated can often withstand this type of ice formation. Plants that are not very hardy may sustain injury to the root system and be severely damaged or killed. Sometimes this is not noticed until the plant fails to leaf out the following spring.

Windy conditions can also cause plant damage through dessication. This is the drying out of the plant. Marginal or leaf-tip burn is characteristic of this problem. Leaves may eventually turn completely brown and defoliate. Dessication occurs because the plant is losing more water than it absorbs.

Frost cracks are another type of injury that can occur as a result of cold temperatures.