How to Avoid Road Salt Damage in Your Garden

Road salt and other de-icers are a fact of life in Minnesota winters, keeping ice from forming on roads and sidewalks. And, just as many pet owners take precautions to protect their animals’ feet, gardeners should give thought to plants that may be affected by road salt.

How Does Road Salt Affect Plants?

snow plow on roadway
Snow means salt for northern gardeners.

Road salts are mostly chloride-based products that form a liquid that freezes at a lower temperature than water. The result is that ice is less likely to form or to cling to sidewalks, roads and other surfaces. According to Rutgers University, road salt affects plants on both their foliage and at the root level. Salt can be sprayed on plants by passing vehicles or it can be absorbed into soil when snow melts in spring.

Too much salt can affect a plant’s ability to absorb water and take up vital nutrients such as potassium and phosphorous. Leaf burn and stem or twig dieback are among the signs of salt damage.

What’s a Gardener to Do?

salt tolerant plants
Grasses and sedum are among plants that tolerate road salt.

Salt is an issue only for plants that are near sidewalks and roadways, and Rutgers recommends that gardeners adjust how they shovel in order to reduce the amount of salt needed. Shovel first to clean the walk, then apply the minimum amount of deicer needed to keep the area safe. You may also want to experiment with salt alternatives, such as sand or kitty litter, which create a less slippery surface without actually melting the ice.

In areas where you cannot control the amount of salt, such as on a boulevard garden, choose plants that tolerate salt better. Conifers, for instance, do very poorly in heavily salted areas because they are not able to shed the salt by shedding leaves. Other plants do much better particularly grasses and those with waxy foliage.

artemisia tolerates road salt
Artemisa ‘Silver Mound’ can tolerate road salt.

Garden blogger Tara Nolan lists several perennials that do very well in a boulevard area where road salt is used, including tall sedum, Russian sage, columbine, butterfly weed (Asclepias tuberosa), Karl Foerster grass and Silver Mound artremisa. Interestingly, many of these plants are ones I planted in a garden bed that got lots of sun and plenty of salt spray. They thrived there!

Other plants that may do well in a salt-strewn area include birch, honeylocust, oak, spirea, willow and little bluestem. The Minnesota Pollution Control Agency has a list of Minnesota plants and their salt tolerance.

 

 

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