Impact of Winter Weather on Plants

— Written By

January brought unusually cold and snowy weather to Onslow County. These low temperatures can cause problems in the landscape including cold damage to plants and the possibility of salt burn from de-icing products.
There are many cold damage symptoms that can show up on plants but brown foliage or dead shoot tips are the most common. Resist the urge to go out and prune cold-damaged plants. We have more cold weather yet to come and the browned leaves and damaged stem tissues will actually protect the rest of the plant from additional damage. Once new growth resumes in the spring, you will be able to see what tissue is alive and what is dead. Then you can carefully remove dead and damaged parts of the plant.
Cold damage can be hard to predict and plants respond differently based on the species and other factors. Young, newly established plants and plants in exposed locations are more likely to suffer cold damage compared to older, established plants and plants in protected locations. Plants that are otherwise under stress or plants growing at the northern end of their range are more susceptible to damage as well.
January brought unusually cold and snowy weather to Onslow County. These low temperatures can cause problems in the landscape including cold damage to plants and the possibility of salt burn from de-icing products.
There are many cold damage symptoms that can show up on plants but brown foliage or dead shoot tips are the most common. Resist the urge to go out and prune cold-damaged plants. We have more cold weather yet to come and the browned leaves and damaged stem tissues will actually protect the rest of the plant from additional damage. Once new growth resumes in the spring, you will be able to see what tissue is alive and what is dead. Then you can carefully remove dead and damaged parts of the plant.
Cold damage can be hard to predict and plants respond differently based on the species and other factors. Young, newly established plants and plants in exposed locations are more likely to suffer cold damage compared to older, established plants and plants in protected locations. Plants that are otherwise under stress or plants growing at the northern end of their range are more susceptible to damage as well.

Impact of Winter Weather on Plants

De-icing products also pose a threat to landscape plants. De-icing products are salts and they can damage plant roots and foliage when they are splashed onto leaves or dissolve in melting snow and run into planting beds. Salt damage can burn evergreen leaves, dry out bud scales and result in damage to the upcoming season’s leaves and flowers. Salts in the soil can displace other minerals resulting in nutrient deficiencies and interfere with water uptake by the roots. The chloride ions from rock salt can be transported within the plant causing leaf burn and die back. Some of these problems will not be obvious until later in the growing season or periods of drought stress.

The closer that plants grow to treated surfaces such as sidewalks or driveways, the more at risk they are of damage. To reduce damage to plants, avoid using de-icing chemicals that contain sodium chloride (table salt, NaCl). Alternative products that do not contain sodium include potassium chloride (KCl), calcium magnesium acetate (CMA) or calcium chloride (CaCl2) as active ingredients. These products are more expensive but are much less likely to damage plants when properly used. Coarse sand and sawdust are simple, natural alternatives to de-icing chemicals. While they do not melt snow and ice, sand and sawdust will help provide traction on slick surfaces.
If you have evergreen plants that have been exposed to sodium chloride spray, rinse the leaves with plain water as soon as possible after temperatures are above freezing. If salt washes off treated surfaces and soaks into the soil around sensitive trees and shrubs, leach the soil by slowly saturating the area with plain water – use a soaker hose or drip irrigation to run for 2-3 hours. We had some heavy rains after our snow event that will help naturally leach some of the salt away.
Luckily for us, salts applied in early winter tend to result in less damage than salts applied in late winter since there is a better chance that the salt is leached away before active root growth in spring.

Written By

Photo of Lisa RayburnLisa RayburnExtension Agent, Agriculture - Horticulture (910) 455-5873 (Office) lisa_rayburn@ncsu.eduOnslow County, North Carolina
Posted on Feb 1, 2018
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