When we think of the effect that winter has on our gardens, we usually think about how cold it gets.

The depth of insulating snow for our plants is another concern. We worry about ice storms breaking limbs of our trees and shrubs.

However, there is another problem that we must consider: salt damage to plants from deicers.

It is crucial that we are safe when we drive and walk during the winter, thus we need deicers.

The most efficient, inexpensive, and widely used chemical for melting snow and ice is common rock salt, sodium chloride. However, the salt may negatively affect many of our plants.

There are two kinds of damage from deicers that we apply to roads and walkways: salt spray and soil-borne salt.

Salt spray can travel up to 1,000 feet from salt-treated roadways by fast-moving traffic and wind. This spray pulls the water out of leaves of conifers and from buds of deciduous trees.

Salt spray is especially damaging in late winter and early spring when leaf buds are beginning to swell. Often, the leaves and flowers on the side of the tree or shrub facing the road do not open or are stunted because of the drying salt spray.

Soil-borne salt damage occurs when the deicer from a road or walkway accumulates in the soil from salt-laden runoff as the snow and ice melt.

The amount that accumulates is affected by the type of soil and its drainage. Soils that are higher in clay can hold more salt than sandy soils.

Unlike a salt spray, soil-borne salt injury develops slowly over time and can cause many complications for plants.

Salts absorb and bind tightly with water, preventing roots from absorbing water. The salt can even pull water from plants, creating a drought-like condition.

At higher concentrations, sodium will compromise the absorption of essential nutrients such as calcium, magnesium and potassium.

With increasingly poorer health from salt damage, the plants become more susceptible to insects and diseases.

Diagnosing soil-borne salt damage can be difficult because symptoms are common with other problems: browning along the edges of leaves; wilting; stunted growth; small, chlorotic (yellow) leaves. and early fall coloration and leaf drop.

What can we do about salt damage to our plants?

First, take steps to minimize it. Try using anti-skid products like sand, instead of salt when possible.

Calcium chloride, potassium chloride and magnesium chloride deicers are less harmful to vegetation than salt when used as directed.

Move plantings away from areas where salt spray or salt-laden runoff accumulates.

Install plants that are salt-tolerant and avoid salt-sensitive species.

If your plants have been damaged by soil-borne salt, applying gypsum (calcium sulfate) in the spring will replace the accumulated sodium ions from the rock salt in the soil.

Gypsum will not change the pH. Gypsum has the added benefit of improving the texture of clay soils (40 pounds per 1,000 square feet).

You can also add organic matter to the affected soil and avoid using inorganic fertilizers.

The soil can also be drenched to remove the salt. Six inches of water will leach out 50 percent of the salt.

The good news is that salt-tolerant trees can protect salt sensitive trees from salt spray.

Often a windbreak or sound barrier of arborvitae is planted along a road. Arborvitae are very salt sensitive.

Instead, plant a row of eastern red cedars, which tolerate salt spray and soil-borne salt. Other good evergreen choices are inkberry holly, blue spruce and mugo pine.

Leaf-losing trees can protect salt-sensitive plants from salt spray. Lilacs, pussy willows and sweet gum slow the winds that carry salt spray.

For flowerbeds where soil-borne salt is likely, try salt-tolerant perennials: tickseed, yarrow, candytuft and butterfly weed.

Also, try daylily or coral bells or late-season bloomers like New England asters and Joe Pye weed.

Always tuck in some annuals among your perennials. Zinnias, calendula and petunias will provide non-stop color and tolerate salt.

Our winter deicers do not need to negatively impact our gardening. By planning well, we can be safe in the winter and have lovely landscapes.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.