Is Road Salt Toxic to Grass?

Road Salts and Lawn Grass

• Road salt used on driveways, sidewalks and roads can often and easily make its way onto lawn grass. When it does, it settles on the grass and is absorbed into the soil. Absorption leads to high sodium levels in the soil beneath the grass, damaging grass roots and leaving it more susceptible to disease problems. Very often, lawns will break out in intermittent brown patches of dead grass, a sure sign of salt abundance on soil.

Salt Tolerance

• Plants of all kinds -- including lawn grasses -- vary in their resistance to salt exposure. Therefore, if you live in a snowy area and happen to be putting in a new lawn, plant a more salt-tolerant species of grass such as 'fults' alkaligrass, Bermudagrass, crested wheatgrass or red fescue. If your lawn is already established, another useful option is to cultivate a "windbreak" of salt-tolerant plants, separating driveways and roads from your lawn grass. Junipers, viburnum, cotoneasters, hydrangeas, and Austrian pines planted near the lawn will absorb salt carried on wind and prevent it from settling into the soil beneath your lawn.

Avoiding Toxicity

• For a less drastic approach to avoiding problems with lawn salt toxicity, there are simple measures you can take to protect your lawn from salt toxicity. Adding a "top dress" layer consisting of compost and gypsum to your lawn grass will counteract the salt in the soil. Additionally, you can water your lawn thoroughly after road salt may have made its way onto the lawn; the water will leach the salt out of the soil and carry it away to an area where it cannot affect the health of your lawn grass.

Other Considerations

• You may find yourself gearing up to install a new salt-tolerant Bermudagrass or wheatgrass lawn only to find that there are no cultivars of that grass that are likely to grow in your climate. Ironic in an unfortunate way is that many salt-tolerant grasses are not acclimated to the colder climates where road salt is often used during winters. Rebecca Brown of the University of Rhode Island is working on a solution to this problem by attempting to increase hybrid cultivars of salt-tolerant grasses that can be grown healthily in colder climates.