Salt

Road Salt and Your Soil

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By Dr. Avishesh Neupane, UConn Soil Nutrient Analysis Lab

When I was a graduate student from Nepal living in New Haven from 2012 to 2014, I kept noticing the same winter aftereffect across town. Along busy streets, the first foot of lawn by the pavement turned yellow and matted, and the road-facing sides of yews and hollies burned while the yard sides looked fine. Coming from a place that does not spread salt each winter, it felt backward. We made the road safer, but the plants and soil paid the price. At UConn’s Soil Nutrient Analysis Lab, we hear versions of this every spring. People send soil from a strip along the road or from a bed near the driveway and say that spot never greens up like the rest.  

You have also likely noticed the symptoms. Fine particles form a crust on the soil surface where water evaporates. Turf browns right at the pavement edge. Buds on the roadside of a shrub fail to break. Evergreens brown on the street side when traffic spray carries salty water, while the interior needles stay green. Vegetable beds that sit too close to plow piles can exhibit poor emergence, tip burn, or slow growth, even when the rest of the garden appears fine.  

What road salt does to soil 

Sodium chloride (rock salt) is the most widely used deicer. Once it dissolves, it separates into sodium (Na⁺) and chloride (Cl⁻). Chloride is highly mobile. It moves with meltwater, so in a wet spring, it can leach through the soil and, where conditions allow, reach groundwater, affecting well water quality. 

Sodium changes how soil behaves. In healthy soil, calcium and magnesium sit on exchange sites; repeated sodium inputs displace them, sealing the surface, reducing infiltration, and making the soil feel tighter right where plants already struggle. Sodium also competes with potassium uptake, so salt-burned spots can look nutrient-deficient even when tests show adequate levels. 

Alternatives to sodium chloride are often less harsh but cost more. Magnesium chloride and calcium chloride melt at lower temperatures but still add chloride and can injure plants and corrode concrete and metal. Calcium magnesium acetate (CMA) is chloride-free and generally gentler, yet it’s pricier and harder to find. 

Lab testing and management options 

If you inform the lab that the sample is from a salt-affected area (such as a roadside, plow pile, or splash zone), they will interpret the numbers with that history in mind and, if necessary, use the appropriate salinity method for your sample. 

  1. Soil pH and texture (and organic matter). Sandy roadside fill flushes salts quickly but is more susceptible to damage due to its low buffering capacity. Heavier soils with more organic matter hold up better but can crust at the surface after repeated salting. For optimal plant health and reduced salt uptake, aim for a pH of approximately 6.5–7.0; your report will include a lime rate if your pH is below this range.
  2. Soluble salts / electrical conductivity (EC). EC shows how salty the root zone was when you sampled. It is most informative right after winter or snowmelt, when salts are near the surface. For mineral soils, labs typically measure EC from a simple soil–water extract. 

    Dense green shrub with numerous small, bright red berries growing along its branches, situated against a brick and white wall in a landscaped area.
    Plants like the Winterberry Holly (Ilex verticillata) may be able to stand up to some salt exposure in the landscape. Some varieties may be more resistant than others. (Photo by H. Zidack)

    Start with prevention. Before winter, top-dress the first 1–2 feet along the road with a thin layer of compost to improve structure and exchange capacity. Keep that strip covered, overseed thin turf, or use a salt-tolerant edge, and ask the plow operator to place piles where meltwater drains to the street or to vegetation that isn’t over your well line. Where meltwater goes matters as much as how much salt you use. 

    After winter, fix what the season left behind. If the roadside sample shows elevated EC, lightly loosen any compacted or crusted soil so that water can infiltrate. Then, leach the area with two or three deep soakings a few days apart to push salts below the main root zone. If a hedge or shrub burns on the roadside year after year, consider moving it back or replacing the front row with more salt-tolerant plants. 

    For chronic hotspots, shift from one-time flushing to long-term protection: use less deicer, keep piles away from beds and wells, maintain dense groundcover in the first foot along pavement, and in harsh exposures, consider stone mulch plus seasonal compost topdressing to help the soil rebound. 

    If your well water tastes salty, check the state’s road-salt guidance and contact your town. When the damage is limited to curb strips or driveway beds, soil testing and better winter practices usually solve it.  

    The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at extension.uconn.edu/locations. 

    This article was published in the Hartford Courant November 23, 2025

    How to Identify and Treat Salt Damage on Plants

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    How to Identify and Treat Salt Damage on Plants
    Laurel Humphrey, UConn Home & Garden Education Center

    From freezing temperatures to blistering winds, the harsh winter elements can pose a challenge for people and plants alike. One common issue many gardeners face during the wintertime is salt damage on plants. While deicing road salts help to ease our troubles by keeping roads, driveways, and sidewalks clear, they only intensify winter damage on the ecosystems and plants nearby. As a country, the U.S. is estimated to apply about 20 million tons of salt per year for public safety on roadways. The most common form of deicing salt used to keep ice from forming on the roads is sodium chloride, or rock salt, which can be very damaging to vegetation. Deicing salts contribute to the damage and dieback of landscape plants each year, however there are steps one can take to identify salt injury and minimize its effects.

    What are Symptoms of Salt Damage in Plants?

    When deicing salts inevitably wash off the roads, they threaten plants both directly through contact with the foliage, as well as indirectly by changing the soil chemistry. In what is known as “spray zone” injury, salt water collects on plant foliage and enters the plant cells directly. This type of salt injury results in discoloration beginning at the margins of the plant and may eventually lead to premature leaf or needle drop. Salt spray can also dry out bud scales, exposing the developing leaves and flower buds to reduce growth later in the spring. Spray zone injury often produces a distinct pattern of damage, where symptoms are restricted to foliage facing the roadside and increase in severity as plants are found closer to the road.

    Another way plants are affected by road salts is when runoff salt water dissolves in the soil and is taken up by plant roots. Within the soil, sodium chloride breaks down into ions that compete with the other nutrients plants need to survive. As a result, plants take in more of the harmful sodium salts and less of the beneficial nutrients they require. Plants tolerate small amounts of salt naturally, but toxic concentrations can result in symptoms of wilting, scorch, and burn. Overall, deicing salt exposure causes symptoms similar to drought and root damage in plants, such as tip browning, bud death, stem dieback, stunted growth, marginal burn and discoloration, and even tree death. These effects may vary depending on the plant species and degree of exposure, with salt applications in late winter thought to be most damaging to plants and less likely to be leached away from roots.

    A row of bushes exhibiting salt damage
    Deicing salt exposure can result in the damage and discoloration of plant foliage along roadsides. Photo courtesy of Joseph LaForest, UGA, Bugwood.org.

    How can Road Salt Injuries be Managed?

    In order to minimize the harmful effects of road salts and be sure your plants will make it to see a healthy spring, there are some steps you can take to reduce salt injury. One obvious option is to limit the use of road salts when possible, especially near lawns and landscapes. This can be done by mixing salt with other materials such as sand or sawdust to help maintain road traction, as well as choosing other salt options like calcium chloride that are less harmful to plants, although more expensive. Gardeners can also protect their plants from salt damage by covering them with materials like wood or burlap, and being careful to plant salt tolerant species near roads and sidewalks. Trees such as hedge maple, paper birch, and Northern red oak are more tolerant to salt exposure than sensitive species including red maple, boxwood, and Eastern white pine.

    While it is not always possible to prevent salt damage from becoming an issue during the winter months, other management strategies can be used to treat salt injury. If you do identify exposure to salt damage in your landscape, be sure to wash salts off plant foliage as soon as possible. Prevent snow piles, sand, and runoff from building up near sensitive plants, and maintain healthy soil salinity levels through the addition of organic matter. The most effective way to minimize salt damage is by leaching salts away from the plant roots. Apply fresh water often to flush salts down through the soil when the ground is not frozen, and plant roots should be less vulnerable to the toxic effects of road salts.

    Laurel Humphrey is a student employee working with the Plant Diagnostic Lab and Home & Garden Education Center. For questions on road salt or if you have any other gardening questions, contact the UConn Home & Garden Education at (877) 486-6271 or www.homegarden.cahnr,uconn.edu or your local Cooperative Extension Center.