February 14, 1997

Help your trees survive damaging effects of road salt

With all the snowfall this winter, trucks have been out on the streets spreading salt and plowing snow more than normal. Salt is used on our roads to simplify our lives as drivers, but it is harmful to plants. Trees and shrubs planted along the roadside are hit with salt spray, which causes bud death, twig dieback, and disfiguration on broadleaf and evergreen trees and shrubs.

The salt spray affects plants above ground as well as below because salt accumulates in the soil. Common symptoms of plants that have been damaged by high salt accumulation include abnormal fall color, needle tip burn, and browning that starts on the edge of the leaf and progresses toward the leaf's middle vein.

"Extensive use of salt causes widespread damage, causing disfiguration of trees and shrubs," says Gary Johnson, urban forester with the University of Minnesota's Extension Service. He says there are several things you can do to prevent salt-related problems:

• Avoid planting salt-sensitive plants close to heavy traffic areas and busy intersections. Salt-sensitive trees include Littleleaf Linden, Sugar Maple, Red Maple, Crabapple, White Spruce and White Pine. Instead, plant salt-tolerant tree species such as Ohio Buckeye, Black Hills Spruce, Ginkgo and White Ash.
  
  
• Plant trees at least 60 feet from the road. Plants that are closer to the road stand a higher chance of being affected.
  
  
• Avoid using de-icing salts on your sidewalks or use smaller quantities. Use coarse sand instead.
  
  
• Protect plants with barriers made out of plastic, burlap or snow fencing.
  
  
• Keep your plants healthy. A healthy plant is better equipped to survive the damaging effects of salt spray and accumulation.

If you would like additional information, consider purchasing a copy of Minimizing De-Icing Salt Injury to Trees, item FO-1413-NR2 (click here for more information), from the University of Minnesota's Extension Service. It's available for $3 plus $2 shipping. Call (800) 876-8636 or (612) 624-4900 for more information. This item is available to disabled persons in alternate formats upon request.

This information is cosponsored by the Minnesota Shade Tree Advisory Committee (MnSTAC) which is a forum for tree advocates to form a collective vision for Minnesota's community forests. Its members represent nurseries; commercial tree services; academic institutions; federal, state and local agencies; and nonprofits.

Web,V4MN,V7,G1
NNRD5445

Source: Gary Johnson, (612) 625-3765
Editor: John Winzenburg, EDS, (612) 625-6243; news@extension.umn.edu

News Page