Find out what risks rodents can cause to your trees over the winter month.
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Every spring, Twin Cities homeowners discover heartbreaking damage to their prized landscape trees—not from storms, disease, or harsh weather, but from rabbits, voles, and deer that spent winter months methodically destroying bark and roots hidden beneath snow cover. By the time the damage becomes visible in March or April, it's often too late to save affected trees.
The culprits? Small rodents and wildlife that view your carefully cultivated landscape as an all-you-can-eat buffet when natural food sources disappear under snow. Voles girdle tree roots beneath the ground, rabbits strip bark from young trunks, and deer browse on branches and buds—all while you're obliviously watching February snow fall.
At Minnesota Landscapes, our ISA Certified Arborists have seen thousands of dollars in tree investments destroyed by preventable rodent damage throughout White Bear Lake, Shoreview, Woodbury, and across the Twin Cities metro. After nearly three decades protecting landscapes through Minnesota's harsh winters, we've learned that February is the critical month for inspection and intervention—before accumulated damage kills valuable trees.
Understanding why mid-to-late winter creates maximum vulnerability helps explain why February inspections are so crucial:
By February, months of snow cover have eliminated most accessible natural food for rodents and wildlife:
Ground-Level Food Is Gone: Grasses, low-growing plants, and fallen seeds that sustained small mammals in November and December are long buried or exhausted.
Bark Becomes Prime Food: Desperate for nutrition, voles, rabbits, and mice turn to tree bark—particularly the nutrient-rich cambium layer just beneath the outer bark.
Evergreen Foliage Looks Tasty: When other food is scarce, deer and rabbits browse on evergreen foliage, particularly arborvitae, yew, and fir—often causing extensive damage to foundation plantings and privacy screens.
Rick Morrison, Minnesota Landscapes' Operations Manager and ISA Certified Arborist, sees this pattern every year: "The worst rodent damage almost always happens in January and February. Early winter, there's still accessible food. By late winter, animals are desperate and will eat anything—including the bark of trees worth thousands of dollars."
Deep snow creates ideal conditions for voles (meadow mice) to work undetected:
Hidden Highways: Voles create tunnel systems beneath snow, moving freely around your yard while completely protected from predators and weather.
Direct Trunk Access: When snow is deep, voles can reach tree trunks and gnaw bark several feet above ground level—areas that would normally be too exposed for safety.
Root Zone Damage: Beneath the snow, voles gnaw on roots and root collars, creating damage that won't become apparent until spring growth fails to occur.
Invisible Until Too Late: Because all this activity happens under snow cover, homeowners have no idea their trees are being destroyed until late March or April when snow finally melts.
Late winter temperature swings make rodent damage worse:
Increased Activity: Warm February days bring increased rodent activity as animals emerge from burrows and tunnels to feed.
Bark Softening: Slightly warmer temperatures make bark easier to chew through, accelerating damage.
Stress Compounds Damage: Trees already stressed by freeze-thaw cycles, winter desiccation, and harsh conditions are less resilient to rodent damage.
Not all trees are equally vulnerable. Kelly Bremer, Minnesota Landscapes' designer and plant manager, has identified the most at-risk species in Twin Cities landscapes:
Fruit Trees (Apple, Crabapple, Cherry): The sweet cambium layer of fruit trees attracts voles and rabbits like candy. Young fruit trees can be completely girdled and killed in a single winter.
Maples (All Species): Norway maples, sugar maples, red maples—voles and rabbits find all maple species particularly tasty. Their thin bark offers little protection.
Lindens: Both littleleaf and American lindens suffer extensive vole damage, particularly at the root collar where trees are most vulnerable.
Honey Locust: Despite thorns on branches, the trunk bark is vulnerable to gnawing at ground level.
Arborvitae: Perhaps the most damaged landscape plant in Minnesota. Deer and rabbits browse arborvitae voraciously, and voles attack roots and lower trunk.
Yew: Both rabbits and deer find yew foliage irresistible. Foundation plantings of yew often suffer catastrophic browsing damage.
Hemlock: Extremely vulnerable to both browsing and bark gnawing. Generally not recommended for exposed Minnesota locations.
Fir (especially Balsam and Concolor): Deer and rabbits browse needles and tender branches, often destroying the shape and health of specimen trees.
Oak (Young Specimens): Mature oaks resist damage, but young oaks with thin bark can suffer significant vole and rabbit damage.
Ash: Young ash trees are vulnerable, though EAB has eliminated most ash from Minnesota landscapes anyway.
Serviceberry: Multi-stem forms attract voles to base, while deer browse on branches.
Redbud: Thin bark makes redbud vulnerable, particularly in harsh winters when other food is scarce.
Spruce (Blue, Norway, White): Generally resist browsing and gnawing, though young specimens still need protection.
Eastern Red Cedar: Native junipers resist most rodent damage due to aromatic oils in foliage and bark.
Birch: Though rabbits occasionally browse, birches resist damage better than fruit trees or maples.
Hackberry: Tough bark and less palatable cambium provide natural resistance.
When Minnesota Landscapes designs comprehensive landscape plans for clients throughout Eden Prairie, Apple Valley, and Mendota Heights, we consider rodent vulnerability during species selection—choosing resistant species for exposed locations and implementing protection strategies for vulnerable favorites.
Don't wait for spring to reveal the damage. Here's what Rick Morrison recommends checking right now:
Bark Damage on Trunks: Check the lower 2-4 feet of tree trunks for gnaw marks, missing bark patches, or exposed wood. Pay special attention to the north and east sides where snow drifts typically form.
Girdling Indicators: Complete or nearly complete bark removal around the trunk circumference is catastrophic—interrupting nutrient and water flow and often killing the tree.
Rabbit Chew Patterns: Rabbit damage shows as clean, angled cuts on small branches and distinctive gnaw marks on bark—typically on branches up to pencil-thickness.
Deer Browse Damage: Ragged, torn branch ends indicate deer browsing (deer lack upper front teeth so they tear rather than cleanly cut). Look for damage 2-6 feet above ground.
Evergreen Browning: Check arborvitae, yew, and fir for brown, dead foliage indicating browsing damage that will become more obvious in spring.
Clear Snow: Carefully clear snow away from the base of vulnerable trees to expose the root collar (where trunk meets roots).
Inspect for Girdling: Voles often work at or just below soil level, girdling roots and root collar while completely protected by snow cover.
Look for Tunnel Systems: Visible vole tunnels at the base indicate active rodent presence and likely damage.
Feel for Loose Bark: Gently press bark at the root collar—if it feels loose or separates easily, voles have likely destroyed the cambium layer underneath.
Photograph Damage: Take photos of any damage you find—useful for insurance claims and for consulting with arborists about treatment options.
Note Patterns: Which trees are damaged? Which sides? How extensive? Patterns help predict and prevent future damage.
Mark Affected Trees: Use surveyor's flags or ribbons to mark damaged trees so you can monitor their spring response.
If your February inspection reveals ongoing rodent damage, immediate action can limit destruction:
Install Physical Barriers Immediately: Even in mid-winter, you can install hardware cloth cylinders around affected tree trunks. Use 1/4-inch mesh hardware cloth, 24-30 inches tall, buried 2-3 inches below soil level.
Clear Mulch and Debris: Pull mulch and leaf litter away from tree bases—these materials provide vole cover and nesting habitat. Create a 6-12 inch clear zone around each trunk.
Disrupt Tunnel Systems: Collapse visible vole tunnels by stomping or using a rake. This temporarily disrupts their movement patterns (though they'll rebuild).
Apply Repellents: Commercial tree trunk repellents containing capsaicin, thiram, or bone oil can deter further gnawing. Apply according to label directions on days above freezing.
Consider Trapping: For severe active infestations, trapping may be necessary. Contact professional wildlife control specialists or your local extension office for guidance.
Don't Paint Wounds: Old advice about painting tree wounds with tar or paint is now discredited—it actually traps moisture and promotes decay.
Don't Attempt Amateur Grafting: Bridge grafting (reconnecting severed bark) is a skilled procedure best left to professional arborists.
Don't Give Up Yet: Even severely damaged trees sometimes surprise us with their resilience. Wait until June before making removal decisions.
Don't Remove Guards Too Early: Keep physical barriers in place through March—rodent damage can continue until natural food sources return in early spring.
For valuable specimen trees or extensive damage, professional evaluation is essential:
Severe Girdling: Trees with 50% or more of trunk circumference damaged need professional assessment.
Multiple Affected Trees: If several trees show damage, you have a systemic rodent problem requiring comprehensive management.
Valuable Specimens: High-value trees—mature specimens, rare varieties, focal point trees—justify professional intervention.
Uncertain Prognosis: If you're unsure whether damaged trees can survive, our ISA Certified Arborists can evaluate and recommend treatment.
Bridge Grafting: For severely girdled trees, skilled arborists can sometimes bridge damaged areas with grafts that restore nutrient and water flow.
Supplemental Support: Proper fertilization, watering, and care can help damaged trees recover by supporting new cambium growth.
Damage Assessment: We evaluate whether damaged trees can recover or should be removed and replaced.
Comprehensive Protection: For properties with ongoing rodent problems, we develop integrated management plans including physical barriers, habitat modification, and landscape design changes.
Rick Morrison emphasizes early intervention: "The difference between a tree that survives girdling and one that dies often comes down to how quickly we identify damage and implement support measures. February inspection means we can start treatment protocols immediately rather than discovering problems in May when it's too late."
Smart homeowners work with Minnesota Landscapes to implement lasting protection:
Physical Barriers Installation: In October and November, before snow falls, we install hardware cloth cylinders around vulnerable tree trunks. Proper installation includes:
Proper Mulching Technique: Mulch provides many benefits, but deep mulch against tree trunks creates perfect vole habitat. Our crews create proper mulching:
Habitat Modification: Reducing vole-friendly conditions throughout your landscape:
When Minnesota Landscapes creates comprehensive landscape plans for properties in Cottage Grove, Eagan, or Rosemount, we incorporate rodent-damage prevention:
Resistant Species Selection: For areas with chronic rodent pressure, we specify naturally resistant species like spruce, juniper, and hackberry rather than vulnerable fruit trees and maples.
Strategic Placement: Vulnerable species go in locations less accessible to rodents—near hardscaping, away from field edges, distant from ground cover.
Diversity Approach: Rather than extensive plantings of vulnerable species (like arborvitae hedges), we design diverse plantings that spread risk.
Integrated Protection: Our designs incorporate natural barriers—groundcovers that voles dislike, strategic hardscaping that limits access, and spacing that reduces shelter.
Kelly Bremer regularly addresses rodent vulnerability during design: "When clients want arborvitae privacy screens, we discuss protection requirements upfront. Sometimes we recommend alternative species that provide similar screening with less vulnerability. Other times we design comprehensive protection systems into the installation plan."
Commercial Repellents: Various products claim to deter rodent damage. Effectiveness varies, but some homeowners find success with:
Reapplication Required: All repellents require repeated application throughout winter, especially after snow or rain.
Professional-Grade Products: Minnesota Landscapes has access to commercial-grade repellents more effective than consumer products.
Raptor Habitat: Hawks and owls are voracious vole hunters. Encouraging raptors through:
Domestic Cats: Outdoor or barn cats significantly reduce vole populations (though they also impact bird populations—a controversial trade-off).
Habitat for Beneficial Predators: Certain beneficial snakes, foxes, and other predators help control rodent populations.
What's at stake if you don't inspect for and prevent rodent damage?
Direct Tree Replacement Costs: A mature maple destroyed by voles represents $2,000-5,000 in replacement costs—and the replacement will take 10-15 years to reach comparable size.
Landscape Investment Loss: If that destroyed maple was part of a comprehensive landscape installed five years ago at $30,000 total cost, you've lost a significant component of that investment.
Property Value Impact: Mature trees add substantial property value. Losing several specimens to preventable rodent damage directly impacts home value.
Emotional Cost: Many homeowners have deep attachment to specific trees—the maple they planted when their child was born, the fruit trees that produce annual harvests, the evergreens that screen an unsightly view.
Domino Effects: When trees die from rodent damage, you lose screening (privacy), shade (increased cooling costs), windbreaks (increased heating costs), and ecosystem benefits.
Compare these costs to prevention:
Physical Barriers: $15-30 per tree for hardware cloth and installation
Professional Fall Protection Service: $200-500 annually depending on property size
Repellent Applications: $100-300 per season
Comprehensive Management Plan: $500-1,000 annually for large properties
The math is compelling—prevention costs a fraction of replacement and loss.
Smart Twin Cities homeowners bundle rodent damage prevention with other Minnesota Landscapes services:
When removing trees in late winter (as discussed in our recent blog), we simultaneously:
When installing new patios or landscape features:
Our exterior lighting systems can support rodent management:
Ongoing maintenance includes:
Don't wait until spring reveals the full extent of rodent damage. Contact Minnesota Landscapes now for professional tree assessment and protection services.
Our ISA Certified Arborists will:
Call 651-457-0000 or visit www.minnesotalandscapes.com
Serving White Bear Lake, Shoreview, Woodbury, Apple Valley, Eden Prairie, Edina, Minneapolis, St. Paul, Mendota Heights, Eagan, Cottage Grove, Afton, Rosemount, Dellwood, and all Twin Cities communities with comprehensive tree care and landscape protection since 1996.
