Protect Trees and Shrubs From Winter Damage
Wisconsin’s harsh winter climate can cause severe damage to plants.
Winter sun, wind and cold temperatures can bleach and dry out evergreen foliage damage
bark or injure or kill branches, flower buds, and roots.
Snow and ice can break branches and topple entire trees.
Salt used for deicing streets, sidewalks and parking lots is harmful to landscape plants.
Winter food shortages force rodents and deer to feed on bark, twigs, flower buds and leaves,
injuring and sometimes killing trees and shrubs.
Here are steps you can take to protect trees and shrubs and minimize injury. Remember, it
all starts with the roots. In the fall, right up to the first freeze, there are two steps you can take
to ensure proper hydration and root protection. Understand that soil temperatures drop much
more slowly than air temperature and that roots of most trees will begin to die if the soil reaches
temperatures below 10°.
Evergreens, newly planted trees and woody plants need to be watered
frequently during the fall (especially during a dry fall season). During a deep freeze (when the
ground freezes) roots can no longer absorb moisture from the soil and become dependent on
what they’ve stored in the fall. The primary cause of winter damage to evergreens is from
dehydration. Evergreens don’t lose their foliage in the winter and will continue to transpire.
If they haven’t stored sufficient water, they may suffer burning or browning of the foliage.
Soil temperatures below 10°F can cause severe damage and kill
the roots of most trees. While it may seem counterintuitive, moist soil is able to hold more
heat than dry soil. In order to maximize root growth in the fall and minimize winter root
injury, a 3 to 6-inch layer of wood chips or organic mulch should be used around your trees,
plants, and shrubs.
Repeated freezing and thawing of soil in fall or spring causes soil
to expand and contract, which can damage roots and heave shrubs and new plantings out
of the ground. A 4- to 6-inch layer of mulch will prevent heaving by maintaining more constant
The proper pruning and trimming of your trees and shrubs
(to eliminate multiple leaders and weak branches) will help to avoid damage caused by snow
and ice accumulation. Tying leaders together, cabling larger trees, or wrapping smaller trees
is an option. Seek assistance from a tree professional, the improper application of these
alternatives can cause more harm than good.
These ties, wraps, and cablings must be
removed in the spring to avoid girdling and return free movement to the stems and branches.
The best overall strategy for protecting your trees and shrubs from animal browsing is to
reduce areas of habitat and erect physical barriers to prevent them from getting to your plants.
Deer, rabbits, and rodents will begin to feed
on foliage, twigs, and bark as their normal food sources become unattainable in the winter
months. The foraging of these animals poses a great threat to the health and life of your
trees, shrubs, and plants. Here are some simple solutions like trunk wrapping to keep your
landscape safe from these critters and their appetites:
Putting plastic tree guards around the bottom of your trees (especially
young or newly planted trees) will keep rabbits and mice from feasting on them. If you live in areas
which accumulate snow, the guards should be well above the snow line. Otherwise, your efforts will
be in vain.
Chicken Wire Barriers – This is the best solution for rabbits. Erecting chicken wire
fences/cages around your trees, shrubs, and plants will keep them out of harm’s way.
Deer and Pest Repellent Spray – Applying a repellant spray to the trunks, branches,
and stems of your trees is a great option, especially if you have numerous trees on your property.
Repellant sprays are easy to come by at nurseries and home supply stores that have a gardening
Trunk Wrapping for Deer Prevention – Deer love to rub their antlers on tree trunks.
That said, if you live in an area where deer graze, it is a prudent idea to wrap your most vulnerable
tree trunks. Take a look at the following video for a smart and inexpensive way to wrap your tree trunks.
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