Is Snow Bad for Plants? What You Need to Know About Your Snow-Covered Garden

Nope! Snow provides moisture to the plants as it melts, but it also has another benefit. “When the soil freezes and thaws daily, there’s the possibility of newly planted ornamentals being heaved out of the ground, exposing their roots to root-killing temperatures,” says Ford. “Snow actually is good for most plants since it provides an insulating layer, which prevents this rapid freezing and thawing of the soil and frost heave.” You also can help prevent frost heave by adding a 2- to 3-inch layer of organic mulch over plantings.

Should You Brush Snow Off Plants?

Perennials will be fine snuggled under a layer of snow, but you should remove heavy snow from low-growing evergreens and trees to prevent damage. “Use a broom to sweep in an upward motion to remove snow as soon as it stops,” says Ford. Don’t wait too long; it’s much easier to remove fresh snow, rather than when it’s been allowed to ice over after a few days.

Resist the urge to shake the branches or to sweep in a downward motion to brush away snow.

“If you sweep downward, you may cause the plant’s branches to break, which you won’t know about until spring. Frost cracks caused by heavy snow and ice are a hidden cause for plant injury that appears in spring and summer,” says Ford.

It’s typically not necessary, but if you have shrubs that are marginally hardy to your zone, you may want to cover the plant with a bed of leaves to insulate around its base and protect its roots. Burlap screens erected on the windward side of broadleaf evergreens also provide protection to prevent winter desiccation (drying) injury, says Ford.

You also can use wooden shrub covers over the entire plant to prevent them from becoming bowed down by snow and ice. These are V-shaped frames which work well for ball-shaped evergreens, which sometimes don’t handle heavy snows well. The only downside is you’ll need someplace to store these covers from spring to early winter.

Some gardeners like to wrap young trees, especially those with smooth bark, with burlap or corrugated plastic to prevent a type of winter injury called southwest damage, says Schmitz. On some young trees, such as maple, the bark is thin, and on sunny winter days, the sap will thaw and run on the southwest side of the tree; it then will rapidly freeze after the sun sets, leading to the bark splitting open on the southwest side of the tree. Wrapping protects young smooth-barked trees from splitting due to these rapid freeze-thaw cycles. Just make sure to remove the wrap in early spring.

Should You Knock Ice Off Plants?

As tempting as it is, trying to remove ice from plants often causes broken branches, says Ford. Let the ice melt naturally; most shrubs and trees will pop back up and recover in time, or you can prune broken branches and limbs as needed in late winter or early spring.

Deicing compounds containing sodium, calcium and potassium chloride aren’t the best for plants or lawns. “Elevated salt levels in the soil can cause plant injury and death,” says Ford. Look for products containing calcium magnesium acetate, or CMA, which is considered the best plant-safe product, derived from dolomite limestone and acetic acid. It does not adversely affect plants and isn’t as corrosive to concrete surfaces, though it is typically more expensive. It’s what’s applied to roads in liquid form before a storm.

Another key is to use the least amount of deicer possible to get the job done. First, remove as much snow as possible mechanically with a shovel or snowblower, then apply deicing materials, as needed; using deicers often can’t be avoided for safety reasons, especially on stairs. “If you apply deicing compound and there are granules left after the moisture dries, you put down too much. It should shimmer, but you shouldn’t be able to see granules,” says Schmitz. Next time, sprinkle it on sparingly, let it do its work, then reassess whether or not you need to add more.

Side note for pet parents: According to the ASPCA, all deicers—even those marketed as pet-safe—can cause your pet to become ill; rinse toes after walks, keep products out of your pet’s reach, and call your vet ASAP if you think you pet has ingested any.

How Will I Know if a Plant Will Recover from Winter Damage?

Sometimes damage does occur. That’s just nature. “It doesn’t mean a tree or shrub is ruined, but it may take several seasons to recover,” says Schmitz. You can prune selectively to remove the damage, and let nature repair itself. However, if a plant is severely damaged, such as a round shrub that has large sections of limbs broken from the center, you may need to replace it.

As for perennials, only time will tell. Don’t be too impatient to give up on them; some don’t pop up until late spring. If you’re not sure about a plant, give it until late May or early June. By then, you should see new growth appearing. If not, it probably didn’t survive the winter. No worries. That just means you can plant something new in your garden!