Each winter, thousands of tons of de-icing salt are applied to state and municipal roads in Northeast Ohio in an effort to keep roads dry, ice-free and safe for drivers.
We also use rock salt and other de-icing materials on our own properties to clear walkways, driveways, patios and parking areas.
But salt has a dark side – it causes widespread damage to trees, shrubs and perennial plants that come in contact with salt spray, and can kill them when it builds up in the soil around the root zone.
So what can you do in winter to protect your trees, shrubs and landscape from the damaging effects of salt?
Preventing Salt Damage
Avoid Using Salt
Not surprisingly, the best way to avoid salt damage is to not use salt. While you can’t control what the state or municipality uses on your roads, you can choose to use alternatives like sand, gravel, or kitty litter on your own property.
Clear the snow away as soon as you can (don’t let it build up) and then sprinkle abrasive material if you’re concerned about slipping.
In high-risk areas, such as steps and walkways, consider using alternative de-icing materials, such as calcium chloride and calcium magnesium acetate.
And if you absolutely must use salt, mix it with warm water to form a brine solution and apply it with a sprayer. Not only is this more effective than straight salt, but you’ll use less sodium.
Protect Susceptible Plants
For plants that are located near a road, or those planted by your driveway or walkway, put up a barrier between the plants and the snow and spray coming off the hard surfaces. Plastic, burlap and snow fencing all work well to keep salt spray away from plants.
Anti-desiccant spray applied before freezing temperatures hit (or if temperatures warm up during the winter) can also help to protect evergreen plants from salt injury.
Keep Plants Healthy
Even salt-tolerant plants can’t stand up to salt damage unless they’re healthy. Be sure to water deeply and mulch areas around plants. Prune when needed, assess and amend soil to correct nutrient deficiencies, and take care of diseases and pests immediately.
Minimizing The Effects of Salt Damage
In spite of your best efforts, salt damage is a fact of winter life here in the greater Cleveland area. But there are some things you can do to reduce the amount and severity of injury to your trees, shrubs and perennials.
Reduce the Amount of Sodium in the Ground
Salt that’s moved into the soil can be reduced by flushing the area with fresh water to leach sodium from the soil. Working gypsum, biochar and/or compost into the top 6 inches of soil can also be helpful.
Wash Salt Off Leaves
As soon as the weather is warm enough, rinse salt spray off evergreen leaves.
Improve the Structure and Drainage of Soils
Compacted soils that can’t drain salt-laden water will make the salt damage problem worse. Improve soil structure by adding compost and create adequate drainage to allow water to dissipate quickly.
Avoid Planting in High Risk Sites
In areas that you know are going to be hit hard by winter salt spray, consider creating a hardscaped area instead of planting trees or shrubs. Rocks, gravel and mulch can make for an appealing landscape.
In general, avoid planting trees and shrubs in the spray zone and areas where salt-laden snow will be dumped from snow plows, snow blowers and shovels.
Use Salt-Tolerant Species
Plant species differ considerably in terms of how much salt they can tolerate on leaves or in the soil. When planting in areas that get more salt, use trees and shrubs that have proven to be better able to cope with salt. If in doubt, give us a call – we’re happy to recommend salt-tolerant trees that are appropriate for the Cleveland area.