How to Protect Young Trees in Winter: Tree Wrap, Sunscald and Rabbit Guards

Updated November 1, 2026

A young tree’s thin bark is easy to damage in winter. Sun warms the trunk on a cold day and the bark freezes again at night, which causes sunscald and frost cracks, and rabbits and voles chew the bark when other food runs short. Here’s when to put tree wrap and guards on in your zone, what to use, and when to take it all off, from university extension guides.

Jump to: Sunscald and frost cracks Which trees need it When to wrap, by zone Choosing and putting on wrap Taking it off Rabbits and voles Fall care If bark is damaged

What sunscald and frost cracks are

• Sunscald (also called southwest winter injury) starts when winter sun warms the bark and wakes dormant cells just under it. Utah State says the newly active cells “lose some of their cold-hardiness and are injured when temperatures drop below freezing during the nighttime hours.” “Research has shown that the south side of a tree can be as much as 77°F warmer on a cold winter day than the north side of the tree.” (Utah State University Extension)
• What it looks like: “discolored bark, bark cracking, sunken areas from lack of growth, or sloughing of surface bark to reveal dead tissue within the damaged area.” Damage is usually on the south or west side of the trunk (Utah State University Extension; UConn Home and Garden Education Center).
• Frost cracks are “vertical openings that can extend deep into the wood of the tree and are most often on the trunk”. UConn says they “are not generally fatal to a tree but they can allow disease organisms and canker pathogens to enter the tree.” They can come back: “This can recur over several winters, causing cracks to reopen and enlarge.” (UConn Home and Garden Education Center)
• Frost crack or growth crack? Normal growth cracks are different: “growth cracks do not go as deep, the heartwood is not exposed, and there is no decay or oozing.” (UConn)

When to wrap trees for winter, and when to take the wrap off

• Utah State: wrap “should be applied in late fall before the risk of freezing temperatures and removed the following spring after the risk of freezing nights has passed.”
• UConn: apply it “in the fall prior to freezing temperatures” and remove it “as soon as the risk of freezing temperatures at night has passed.”
• UMN: “Put the wrap on in the fall and remove it in the spring after the last frost.” Texas A&M Forest Service also says to remove it “in the spring after the last frost” (Texas A&M Forest Service).
• Oklahoma State: “Normal application of tree trunk wraps is October to March for the first two growing seasons.” “Wraps should be removed each spring prior to spring growth.” (Oklahoma State University Extension)
• Hardware cloth guards for rabbits and mice go on before snow: “Be sure the mesh cylinder is in place before the first snowfall” (Iowa State, Iowa State University Extension).

The table turns that rule into dates: wrap by your typical first fall frost, and take the wrap off after your typical last spring frost. In zones 3 to 7 the typical first frost has already passed by early November, so wrap now; zone 8 usually reaches it around Nov 10, and in zone 9 and warmer it is still ahead. Enter your ZIP in the planner for the dates at your nearest NOAA station.

About this table: For each ZIP code we use the nearest NOAA NCEI 1991–2020 U.S. Climate Normals station’s 50%-probability 32°F frost dates (half of years frost earlier in fall or later in spring). Median across the zone’s ZIP codes, with the 10th–90th percentile range. Source: data/zonefrost.json, from NOAA NCEI 1991–2020 U.S. Climate Normals. In zones 11 to 13 frost is rare, so no wrap dates are shown; none of the sources above covers trunk wrap in frost-rare climates.

Which tree wrap to use, and how to wrap a tree trunk

• White or light-colored only. UMN: “Use a white commercial tree wrap or plastic tree guards. Do not use brown paper tree wrap or black colored tree guards, as they will absorb heat from the sun.” Utah State: “White tree wrap reflects light away from the trunk and limbs and keeps the bark surface temperature cooler.”
• Wrap from the bottom up, loosely. Oklahoma State: “Tree wraps should be applied loosely from base up to the first branch by overlapping for a shingle effect.” “Plastic wraps should fit loosely and include holes or slits for good air movement.”
• Plastic or paper? “Plastic wraps may provide better protection than paper wraps against lawn mower, weed-eater, and rodent damage.” (Oklahoma State)
• How many winters: Utah State says “Use tree wrap for a minimum of two to three winters after planting.” UConn says 2 to 3 winters “until the bark thickens.” UMN says to wrap newly planted trees “for at least two winters and thin-barked species up to five winters or more.”
• Other ways to shade the trunk: a light-colored board or an opaque fence on the south and west side of the tree. Some orchardists paint lower trunks with white latex paint; Utah State says to “use interior latex paint as some exterior paints contain antimicrobial agents that can be damaging to the tree.” “Paint can also be diluted 1:1 with water.” (Utah State University Extension) Montana State also lists white latex paint (Montana State University Extension).
• Lower branches help too. Iowa State: “The most reliable ways to reduce the incidence of sunscald is to leave lower branches on trees for as long as possible, avoid unnecessary wounding of the trunk, and prevent drought stress by properly watering young trees for the first two to five years.” Oklahoma State: “A twiggy trunk is preferable to tree wraps”, though not every tree has enough twigs.

Why tree wrap has to come off in spring

• Moisture and pests. UConn: “Wrap left on once the temperatures have warmed can keep the bark damp, encouraging disease. It may also harbor pests.” Texas A&M Forest Service removes it “to avoid insects living under the material during the summer.”
• Girdling. “During spring growth, the trunk expands and increases in size. Wraps too tightly wrapped or left on during this time may result in constriction to the trunk.” (Oklahoma State) Montana State says to remove wraps and guards in spring “to prevent constriction and girdling.”
• Check it over winter. Misused wraps can cause “trunk girdling or constriction, insects, diseases, and excessive bark moisture.” “Periodically inspect the wraps for trunk damage and insects.” (Oklahoma State)

How to protect trees from rabbits and voles in winter

UMN says mice, rabbits, voles and deer “girdle trees and shrubs by chewing through the bark.” Iowa State: if the damage “fully circles and girdles the tree, it will likely not survive.”

• Hardware cloth cylinders. UMN: “Protect tree trunks with cylinders of ¼-inch mesh hardware cloth around the trunk of the tree about 6 inches away from the trunk.” “For mice, the cylinder should extend 2 to 3 inches below the ground line. For rabbits, the cylinder should extend 18 to 24 inches above the anticipated snow line.” “Make sure there are no gaps between the bottom of the mesh cylinder and the ground where animals could crawl under the fencing.” Iowa State gives the same depth and height (Iowa State University Extension).
• Plastic guards on small trees: “For small trees, plastic tree guards are also effective.” (UMN)
• Voles “do the most harm to small trees and shrubs when they chew on the bark, often hidden below winter snow.” UMN: “Prevent vole damage to tree bark by encircling the tree with a light colored tree guard”; “The guard should be tall enough to reach above the snow line in the winter.” “Make sure that the guard is loose enough so that it does not constrict the tree.” (University of Minnesota Extension)
• Remove the cover they hide in. “Cut grasses and other vegetation short in late fall within 2 feet of young trees to reduce protective cover for mice and voles that might feed on trunks and stems.” Removing brush piles also discourages rabbits (UMN).
• Repellents are not poisons; UMN says a repellent “simply makes plants taste or smell bad to animals.” UMN: “One application of a repellent is usually enough for the entire dormant season.” Iowa State: “Animals may not be deterred by repellents if feeding pressure is high.”
• Leave the cylinder on all year? The sources disagree. UMN says the hardware cloth “can be kept on year-round.” Iowa State says “Do not leave the mesh cylinder on all year. Leaving the metal mesh wrapped around the tree can restrict growth or cause girdling.” If you leave one on, keep it loose and well away from the trunk, and check it each spring.
• Deer browsing and fencing are covered in how to protect shrubs in winter.

Fall care that lowers the risk

• Water before the ground freezes. UConn: “Be sure to water drought stressed trees up until a hard frost.” Utah State: “make sure trees are fully hydrated in the fall before the ground freezes.” For how much water, see watering until the ground freezes; for dates, first hard freeze dates by zone.
• Mulch the base. Utah State says a layer of mulch around the base “will help conserve soil moisture and moderate temperature.” Texas A&M Forest Service: “A two- to three-inch layer of mulch should be spread around the base of the tree”, kept “about two inches away from the tree’s trunk.” Shredded leaves work: see what to do with fall leaves.
• Skip fall fertilizer. UConn: “Don’t fertilize trees in late summer to avoid a flush of new growth that may not harden off before winter. If you must fertilize in the fall do so after the leaves have dropped or in the spring.”
• Keep mowers and string trimmers off the trunk. UConn: avoid using them “close to the trunk to prevent damage that could expand during the winter.”
• Next time you plant: “Susceptible species should be planted where they do not have a strong south-southwest exposure.” (UConn) Utah State suggests planting susceptible trees to the north and east of buildings or evergreens.

If the bark is already damaged

• Don’t paint or seal it. UConn: “Damaged areas should not be painted or sealed but allowed to heal naturally.” UMN: “Do not apply paint, tar or a commercial tree wound dressing to the open wound.” Utah State says the same, and Iowa State says so for bark damaged by animals.
• Trim loose bark cleanly. UConn: “A knife dipped in a 10% bleach solution may be used to trim away any excess bark.” UMN: “Trees will typically heal themselves through new growth of the inner bark or along the edges where the bark splits.”
• After rabbit or vole damage, Iowa State says to “Provide adequate moisture through the spring and summer and monitor closely as these areas are more likely to see secondary damage from diseases or insects.”
• Then protect it next winter. UMN: “Wrap the tree in winter to prevent further sunscald.”

More guides

Protect shrubs in winter When to prune trees When to prune fruit trees First hard freeze dates What to do with fall leaves November garden tasks by zone ZIP planner