Well, it’s that time of year when we all have to remain vigilant in the battle against frost with our favorite garden plants.
It may be that you have already noticed signs or symptoms of what the frosts of the past few weeks have done to your photosynthetic friends, typically in the form of blackened and wilted leaves or stems. However, cold damage may not be apparent in the plant for several days or weeks.
To determine if your plants have been damaged by the cold, wait several days after a freeze and remove several buds, stems and leaves (if present) from the plant. Using a sharp knife or razor blade, cut a cross section of the bud’s top. If there is any discoloration in the bud, they have been damaged.
To determine if stems have been injured by the cold, peel the bark back to reveal the cambium layer (the layer directly under the bark). If there is any black or brown discoloration, damage has occurred.
Leaf damage may appear as obvious black or burnt foliage, usually occurring at the tip of the branches. Damage on buds, stems and leaves may be localized and the entire plant may not be affected.
Although very little can be done to revive plants suffering from the extreme effects of freezing, not all hope is lost. Once you have determined the extent of the damage, prune away the dead tissue of plants and the dead wood of trees. If localized damage has occurred to the foliage or stems, prune several inches below the injured tissue.
Although injured buds may reduce or eliminate flowering or leaf emergence in the spring, no pruning is necessary. Proceed with caution when pruning away the dead tissue. Waiting to prune after freezes have passed will guard against removing living wood.
The Farmer’s Almanac indicates we may be in store for some more cold weather in February as well, so it might be wise to wait until after the next possible freeze to do the pruning.
The best way to avoid winter damage is to select appropriately hardy plants. Use plant hardiness zone maps to select plants for particular locations. Within a hardiness zone, consider using only plants adapted to a lower number if your planting site has particularly harsh conditions.
If you’re not sure the plants you own are within our hardiness zone (8B), feel free to contact me by phone or email. I’d be happy to help.
Tips for prepping in the future:
Allow plants to harden in the fall before cold weather begins. Try to avoid stimulating new growth by applying excessive nitrogen or pruning in early autumn. Plants that are diseased or deficient in nutrients are more susceptible to winter injury than healthy ones. Corrective measures should be taken in time so they won’t affect cold acclimation.
Avoid low spots that can create frost pockets and sites that can have rapid changes in temperatures. Flowers and leaf buds can be damaged when they are prematurely stimulated to open by warm days, and then subjected to freezing temperatures at night.
Pack potted plants close together and cover them with a translucent plastic sheet that does not touch plants. Mulch or mound soil around pots and balled and burlapped plants will insulate the roots. If you have brought plants indoors, it is safe to move them back outdoors when temperatures are above 45 degrees on average.
Please reach out to the Bryan County Extension office if you have any other questions about frost or cold damage. Email us at uge3029@uga.edu or call at 912-653-2231.
