Remedies for Salt Damage in Plants

Causes of Salt Damage

• Most salt used to de-ice roads consists of rock salt, which is primarily sodium chloride. When exposed to water, the sodium chloride separates into sodium and chlorine, both of which damage plant material. Chlorine is particularly detrimental; it is drawn into the plant in the contaminated water and accumulates in the leaves. Plants can also directly absorb salt upon contact from salt water splashed onto plants. The most salt damage occurs when snows and ice with trapped salt melt during plants' spring growth period.

Signs of Salt Damage

• Because salt damage occurs most often in the spring, new spring foliage may mask the damage to the plant before measures can be taken to alleviate the effect of overexposure to salt. Look for stunted growth, particularly in comparison to plants farther away from the salt exposure. The leaves of plants exposed to salt often brown at the edges or die due to the buildup of chlorine in the foliage. On deciduous plants, you may see a "witch's broom" form, which is a growth of small spindly twigs on the branches.

Treating Salt Damage

• If you fear that too much salt has entered soil that you intend to use for planting, flush the soil with 2 inches of water over a two- to three-hour period for three days. Only do this after the ground warms in the spring. This may also help areas where you have already planted trees, shrubs or other plants. Adding organic material such as compost can add different nutrients to salt-leached soil and help neutralize the presence of salt.

Preventing Salt Damage

• To prevent salt damage to plants, use less salt when de-icing driveways or walkways that are adjacent to plants. Consider using sand or cat litter instead of salt to create traction. Be particularly careful to limit salt application on driveways and walkways on inclines and where water tends to stand and refreeze. Salt only after shoveling snow to reduce the spread of salt water from snow run-off. Finally, plant salt-resistant trees and shrubs such as mountain pines, sumac and white ash trees next to sidewalks and driveways.