Cold damage can be a problem for ornamentals. During late summer and early fall, ornamentals go through cold acclimation. This process is brought on by the short day light hours and cooler temperatures of fall. This winter preparation or acclimation time can be affected by the local weather conditions, the plants you select in the first place and you care of the plants during the growing season.

There are options that can help your landscape items survive winter weather. Today, I will share information from UGA publication by Bob Westerfield, Extension Horticulturist, and Dr. Orville Lindstrom, Professor of Horticulture.

First, what are types of cold damage and resulting conditions. Cold damage can be seen on all parts of a plants. Damage can happen on the roots, stem, leaves, trunk and fruit. Most folks will see damage on the stems and leaves first. You will see mushy areas that will appear brownish-black in color. This is the results of plant tissue death when ice actually forms in the plant cells. According to Westerfield and Lindstrom, an acclimated plant can handle this damage while a non-acclimated plant may become badly damaged or not leaf out the following growing season. Another type of damage is associated with cold and windy conditions. This damage is desiccation loss. This is when the plant dries out greater than the plant is absorbing moisture. You will see leaf scorching or tip burn followed by possible complete leaf browning or defoliation.

Here is a tip if you suspect bud damage. Remove a few buds and cut them open. Cold damaged buds will appear brown or dark in color. Hopefully, inside of the bud will be green which will indication no damage. Another potential damage is bark splitting. The problem with bark splitting due to cold weather is reduction in nutrient and water transfer. It can appear as loose bark on the trunk which will then form a frost canker in the dead area of the trunk. The area can get dark and moist and can lead to death.

Now I would like to share tips on how to cut down on damage. The first tip is easy. Select proper plants for our area. Look for plants that have not only good cold tolerance for our area, but pay attention to how they handle the summer heat of NW Georgia. You also need to investigate your landscape for what you feel are the warmest and potentially coldest areas according to Westerfield and Lindstrom.

Coldest spots are normally on the north or northwestern area of the landscape and in the lowest areas. The lowest areas will be where cold air will settle. Take this information to heart when selecting planting sites based on potential winter injury for some items. Don’t forget about if you plants are full sun or shade items.

Proper nutrition help ornamental tolerance to cold injury. A properly fertilized plant should be in better shape and will acclimate to cold easier. Also fertilize at the correct times. Stay away from fertilizing with high nitrogen fertilizers in fall. This causes new growth at the wrong time. This can lead to cold injury.

Also prune at the right time. Most ornamentals need to be pruned in late winter or early spring. Pruning in late summer or early fall causes new growth at the wrong time. This makes the plant more easily cold damaged and could even kill the plant. Windbreaks such as buildings and evergreen trees can help protect plants from cold winter wind damage.

Westerfield and Lindstrom state that covering and saving radiate heat can help plants. Mulching plants help reduce heat loss and keeps temperatures less variable. You can cover plants with a sheet, blankets or even cardboard when cold weather is predicted. Try to cover to the ground to save the heat. Remove cover during the day to allow for ventilation. Do not cover with plastic covering. Plastic can cause too rapid heat change that can damage the plants. Finally, check the water needs of you plants before a cold period and water if necessary. A moist soil will keep more heat so higher temperatures around the plant. You can mulch too to help conserve soil moisture. For more information contact gbowman@uga.edu or Gordon County Extension at 706-629-8685.