Protecting Evergreens from Ice Damage

Cory Tanner,
Clemson University Extension Agent

Evergreen trees and shrubs are prone to unsightly damage from ice storms. They can be splayed open like a blooming onion or flattened like a pancake by heavy ice loads. Damaged shrubs sometimes resurrect themselves in a matter of days or weeks; other times, they require severe pruning and a long restoration period. Fortunately, diligent gardeners can take a few actions to prevent serious ice damage.

The excessively bent branches on an improperly pruned evergreen may not upright themselves after an ice storm.
The excessively bent branches on an improperly
pruned evergreen may not upright themselves after an ice storm.
Cory Tanner, ©2014, Clemson Extension

The first strategy is to start out right! Many conical evergreens – such as magnolias, cedars, junipers and some hollies - tend to develop multiple stems or trunks. This results in weak branches at the shrub’s base, which can allow the plant to split apart in a storm. Avoid this problem in the beginning by only selecting new plants that have a single main stem and avoid plants with multiple leaders altogether. Once the plant is in your landscape, prevent this problem from developing when it is young by simply pruning out any stem, other than the main trunk, that is growing in a strong vertical direction, i.e., competing with the central stem. By doing this early, the main stem will become dominant and your work is essentially complete since single-stemmed trees and shrubs are less likely to suffer storm damage.

Severe ice damage to an improperly pruned magnolia.
Severe ice damage to an improperly pruned magnolia.
Cory Tanner, ©2014, Clemson Extension

Another method, requiring less foresight but equally successful, is to lightly tie-up the plant before the storm. This simple measure could be the difference between minor damage and complete shrub restoration. With a roll of twine (preferably a biodegradable product like jute), tie the loose end around a stem near the plant’s base. From there, loosely wrap the twine around and gradually up the bush, until about three-fourths of the plant is encircled. At that point, secure the twine to the end of a stem. The spiral should be tight enough to keep stems in place without being severely flexed. The goal is to prevent stems from spreading apart, but not to immobilize them. This strategy will be successful on any evergreen that is small enough to tie-up safely.

Trunks may even split apart on improperly pruned evergreen trees.
Trunks may even split apart on improperly pruned evergreen trees.
Cory Tanner, ©2014, Clemson Extension

Leave this restraint in place until all ice has melted. There is no harm in leaving it on longer, however, for protection in case of another storm, but make sure the twine is removed before new growth begins in the spring. Discard any twine tied or wrapped around individual stems that could girdle them.

Lastly, resist the temptation to remove ice from your plants. This well-intentioned act can result in unnecessary damage to branches. It’s best to let the ice melt naturally.

We never know when the next ice storm may strike, but the next time milk and bread start disappearing from grocery shelves, take steps to make sure you and your shrubs are prepared.

A well-pruned magnolia can withstand a moderate ice storm with only minor damage.
A well-pruned magnolia can withstand a moderate ice storm with only minor damage.
Cory Tanner, ©2014, Clemson Extension

Evergreens Commonly Damaged
by Ice & Snow Loads
Arborvitae (Thuja spp.)
Boxwood (Buxus spp.)
Cedars and Junipers (Juniperus spp.)
Hollies (Ilex spp.)
Live Oak (Quercus virginiana)
Leyland Cypress (xCupressocyparis leylandii)
Southern Magnolia (Magnolia grandiflora)
Wax Myrtle (Myrica cerifera)

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