Winter weather can be challenging for both plants and their owners. While people are bundling up, plants are hanging on for dear life.
Humans aren’t the only ones suffering winter’s wrath. Plants can have quite an ordeal with winter weather. Freezing temperatures can result in ruptured tissue, which can affect the entire plant or just a part of it. Shrubs may have a branch that gets freeze damage and has a large dead chunk. Trees can exhibit winter damage, such as young southern magnolias dying back to the ground in extreme cold weather. Localized damage can appear as split wood, caused by water freezing and expanding.
Heavy snow and ice can cause broken branches for trees and shrubs, especially when accompanied by strong winds. Snow and ice can also lead to necessary de-icing, which can ultimately harm plants.
Deicers can contain a variety of ingredients, but rock salt is the most common. Rock salt is composed of sodium chloride. Other deicers might use magnesium chloride or calcium chloride. Sodium is the biggest culprit here, but any buildup of salt can harm plants. The most plant-safe deicer is CMA, or calcium magnesium acetate. However, practices that limit salt use can also be safer for plants.
Pre-applying deicers can help keep sidewalks clear and prevent the accumulation of snow and ice. Physically removing snow also prevents build-up, compaction, and freeze-thaw layers. If a retroactive salt treatment is necessary, only treat the necessary areas, such as walkways, stairs, and driveways. Deicing salts work best when spread out and not piled. Use an application tool to ensure that hand-scattered salt has evenly spaced granules and not piles.
Salt damage to plants can occur both quickly and slowly. A large dispersal of salt occurs when traffic on roads kicks up salt spray, which can travel hundreds of feet. In neighborhoods, homeowners can overapply salt onto and around plants. The last method salt can infiltrate a plant’s space is through runoff. Salty runoff can dump into garden beds and street tree basins.
The damage from aerial salt spray can lead to scorched, brown leaf tips, most notable on evergreens. Soil salt can damage roots, compete for nutrients, and degrade soil health. Plants suffering from soil-salt buildup often exhibit symptoms similar to those of drought stress or nutrient deficiencies. Salts that get taken up by the roots can also affect the foliage.
Some examples of salt tolerant plants include honeylocust, some junipers, and eastern red cedar. Salt sensitive plants include American hornbeam, boxwood, beech, and lindens.
Please try to keep plants on a low-salt diet this winter. Prevention is always easier than remediation.
For more information, please contact Kenny Dodson, Horticulture Extension Agent, [email protected], 620-670-5018.
