{"id":16142,"date":"2019-12-27T11:21:53","date_gmt":"2019-12-27T14:21:53","guid":{"rendered":"https:\/\/www.lawnstarter.com\/blog\/?p=16142"},"modified":"2024-09-11T14:06:47","modified_gmt":"2024-09-11T17:06:47","slug":"road-rock-salt-reduce-plant-damage","status":"publish","type":"post","link":"https:\/\/www.lawnstarter.com\/blog\/landscaping\/road-rock-salt-reduce-plant-damage\/","title":{"rendered":"Reducing Plant Damage from Road Rock Salt"},"content":{"rendered":"

It\u2019s a miracle-worker for road crews trying to keep highways clear of snow and ice, but once the cold breaks it can leave your landscape withered.<\/span><\/p>

Road salt cuts through snow and ice like magic, leaving dry and safe roadways when everything else is covered in white.\u00a0 Unfortunately for your lawn and landscape, the salt doesn\u2019t magically disappear. It soaks into your soil and gets absorbed by your turf and your favorite plants. Once winter breaks, it becomes a real problem, especially in the coldest, iciest areas.<\/span>\u00a0<\/span><\/p>

\u201cSalt is a pretty good weed killer in itself,\u201d says Bill Craig, ag services director for Marshall and Pennington counties with the University of Minnesota Extension.<\/span><\/p>

\"Bill
Bill Craig, University of Minnesota Extension<\/figcaption><\/figure>

Craig says Minnesota is widely known for its use of road salt. Also known as rock salt, sodium chloride, and halite, road salt is the most widely used de-icer due to its relatively cheap cost, and the fact that it works. In the Twin Cities alone, 365,000 tons of salt are dumped on the roads in winter, <\/span>polluting lakes<\/span><\/a> and other waterways with its runoff.\u00a0\u00a0<\/span><\/p>

While the state is <\/span>studying ways to cut its use<\/span><\/a> by applying it more smartly, salt appears to be in the winter forecast for landscapes in Minnesota<\/a> and every other state where icy roads are common.\u00a0<\/span><\/p>

When moisture follows, that salt runs off into your yard, affecting plant growth and maybe killing the plants it reaches.\u00a0<\/span><\/p>

Homeowners also tend to find salt damage along the edges of concrete surfaces like driveways and sidewalks, Craig says, even when they\u2019re applying the salt themselves.\u00a0<\/span><\/p>

Want to avoid salting the earth in your own front yard? Here\u2019s what you need to know.<\/span><\/p>

A Big Salty Problem<\/span><\/h2>

Salt is an important part of keeping roads open while snow covers everything else, but the amount of salt spread on land surfaces around the United States is astounding.<\/span><\/p>

An estimated 20 million tons of salt is scattered on the country\u2019s roadways annually, according to the <\/span>Earth Institute at Columbia University<\/span><\/a>.\u00a0<\/span><\/p>

That\u2019s about 123 pounds or every single person. And that doesn\u2019t take into account what\u2019s spread on sidewalks or driveways by homeowners.<\/span><\/p>

Chemically, it\u2019s a lot like the table salt you put on your eggs in the morning, that is, sodium chloride. Those molecules separate once the salt is dissolved in water creating a solution of chloride ions and sodium ions, which interfere with the water\u2019s ability to bond together and form ice.\u00a0<\/span><\/p>

It\u2019s called freezing point depression, and while that part has been long understood, the lasting effects of that salt on the land have not.\u00a0<\/span><\/p>

Columbia cites studies showing that more than a third of contiguous U.S. has increased in salinity in recent decades. One <\/span>study<\/span><\/a> in New York found nearly half of 125 sampled wells in Dutchess County had sodium concentrations exceeding EPA guidelines.\u00a0<\/span><\/p>

The effect of that salt spreads in all directions. It not only contaminates soil and harms plants sprayed by passing cars, it affects animal, insect and aquatic life too, as well as drinking water sources.<\/span><\/p>

How Salt Hurts Plants<\/span><\/h2>
\"Highway
Highway rock salt accomplishes its road-de-icing goal, but at a cost to landscapes and waterways. Credit: James St. John<\/a>, CC 2.0<\/a><\/figcaption><\/figure>

So what does this artificial salinization mean for the plants in your yard? Nothing good.<\/span><\/p>

\u201cMost plants can\u2019t tolerate a lot of salt,\u201d Craig says.<\/span><\/p>

The Iowa State University Cooperative Extension <\/span>explains<\/span><\/a> why.<\/span><\/p>

When too much salt accumulates in the soil, most typically the areas closest to the road, it can reach toxic levels that keep plants from absorbing enough water, no matter how wet the soil is.\u00a0<\/span><\/p>

When salty water is sprayed from passing cars onto your shrubs or trees, it dehydrates the plant tissue.<\/span><\/p>

Your favorite lawn feature isn\u2019t immune. Landscape plants such as trees, shrubs, perennials and turfgrass are all susceptible to salt damage, and spray from passing vehicles is particularly harmful for evergreens.<\/span><\/p>

What Salt Damage Looks Like<\/span><\/h2>

Grass<\/span><\/h3>

What many homeowners find is thin or dead grass along their driveways, says Craig. Over the winter, they\u2019ve been adding salt to keep the driveway free of ice.\u00a0<\/span><\/p>

But as it slowly runs off, the de-icer builds up in the soil next to the concrete and kills the grass growing there.<\/span><\/p>

Trees<\/span><\/h3>