Road Salt Damage on Lawns and Shrubs: Prevent It Now, Fix It in Spring

Every spring in the snow belt, there's a brown strip along every driveway, sidewalk and street. The grass is dead or thin, the shrubs facing the road have brown needles on one side, and the boulevard trees struggle. That's salt damage. You can't stop the plows, but you can do a lot to limit it, and fall is when to get ready.

How salt hurts plants

Most de-icers are chloride salts: sodium chloride (rock salt) is the most common. Salt damages plants two ways:

• In the soil: salt dissolves in meltwater, soaks into the soil, and makes it harder for roots to take up water. Sodium also damages soil structure. Grass along the curb dies of what is basically drought, even in wet soil.
• On the plant: salty spray thrown by plows and passing traffic coats evergreen needles and twigs and burns them. That's why the road side of a pine or arborvitae browns while the house side stays green.

Before winter: prevent the worst of it

1. Mark your edges. Put reflective stakes along the driveway and walks so plows and shovelers know where the lawn starts.
2. Choose where the snow goes. Don't pile salty snow from the driveway on the same patch of lawn or around shrubs all winter.
3. Wrap or screen evergreens near the road. A burlap screen (not wrapped tight against the plant) on the street side blocks salt spray. Leave an air gap and keep the top open.
4. Water deeply this fall. Well-watered plants handle salt stress better. See watering trees before the ground freezes.

During winter: use less, use smarter

• Shovel first, melt second. De-icer works best on the thin layer left after shoveling.
• Use the least that works. A coffee mug of rock salt can cover a lot of driveway. Most people use far too much.
• Consider alternatives for the areas next to lawns and beds: calcium magnesium acetate and calcium chloride are generally less harmful to plants than sodium chloride, though they cost more. Sand adds traction without melting anything.
• Sweep up leftover salt and sand after storms.

Spring: flush and repair

1. Flush the soil. Once the ground thaws, water heavily along salted edges (an inch or more) to leach salt down below the root zone. Spring rain helps.
2. Rake out dead grass and reseed with salt-tolerant grasses. Some fine fescues and certain alkaligrass varieties tolerate salt better than Kentucky bluegrass; ask a local seed supplier about a "roadside" or salt-tolerant mix.
3. Gypsum is sometimes recommended to help soils damaged by sodium; it helps soil structure where sodium has built up, but it doesn't remove salt from plants. A soil test can tell you if sodium is a real problem.
4. Prune brown, dead twigs on shrubs once new growth shows you what's alive.

Plant smart

If the same strip dies every year, plant tougher things there: salt-tolerant shrubs and groundcovers, or ornamental grasses that can be cut back each spring.

Salt is part of life up north. A little planning in October means a lot less brown in April.

Photo: 388 Greenwich Street Plaza td (2022-02-01) 016_016.jpg) by Tdorante10, CC BY-SA 4.0.

Related: When to Stop Mowing for the Season (and How Low the Last Cut Should Be)