The Quiet Marathon of Winter: How Trees Survive the Freeze

By late November, the vibrant canopy of autumn has vanished. Deciduous branches stand bare against the grey horizon, while evergreens take on a darker hue. To anyone watching the season turn from the warmth of a living room, it feels as though the natural world has powered down for a peaceful winter rest.

Yet when spring arrives and snowbanks recede, many yards reveal a scene of quiet destruction. Prized arborvitae hedges stand scorched a brittle bronze. Young maples show long, weeping splits down their bark. Heavy boughs lie fractured across the grass after an ordinary storm. It is easy to blame a single night of bitter sub-zero cold, but tree physiology tells a different story. Winter damage is rarely an accident that happens overnight. It is a compounding endurance trial that unfolds over months.

The common misconception is that trees become completely inert in freezing weather. Evergreens never stop working. Their needles continue to transpire, releasing moisture into the dry air. On clear, windy winter afternoons, that water loss accelerates rapidly. The trouble begins beneath the surface: once freezing temperatures turn the soil solid, root systems cannot absorb a drop of water to replace what was lost. The resulting cellular drought, known as winter burn, leaves needles parched and dead. While hardy trees can sometimes push new growth from surviving buds in spring, needles that have turned completely brown will never recover.

Deciduous hardwoods face a different threat: thermal whiplash. On a bright midwinter afternoon, low-angle sunlight warms the southern and southwestern sides of a tree trunk. This sudden warmth coaxes dormant cells beneath the bark into waking up. But when dusk falls, ambient temperatures crater within hours. Those active cells freeze and rupture instantly, leaving behind dead, peeling patches called sunscald. In severe cases, the outer sapwood cools and contracts far more quickly than the dense heartwood inside. The resulting mechanical tension rips the wood open with a startling crack that sounds like a rifle shot across the yard.

Meanwhile, life beneath the snowpack carries its own dangers. When deep drifts bury everyday food sources, hungry wildlife turn to our backyards. Deer browse tender terminal buds, while rabbits stand atop packed snow to snip off low twigs. Worse still are voles. These small rodents tunnel beneath snow and thick groundcover, quietly gnawing away at the tender bark right at the tree’s root flare. If they strip a complete ring around the trunk—an injury known as girdling—they sever the vital vascular tissues that transport sugars between the canopy and roots, quietly starving the tree to death.

Preventing this seasonal toll does not require elaborate tools or harsh chemicals. It simply takes a few thoughtful steps in late autumn while the soil is still workable:

• Hydrate deeply: Giving trees a thorough soaking before the ground freezes solid banks moisture and provides natural insulation, as moist earth holds heat far better than dry dirt.

• Rethink your mulch: Spread a two- to four-inch blanket of shredded bark across the root zone to stabilize soil temperatures, but keep it pulled several inches back from the trunk. Piling mulch against bark traps fungal decay and offers an inviting winter refuge for tunneling voles.

• Shield vulnerable bark: Wrapping young, thin-barked trunks in breathable, light-colored tree wrap reflects winter sunlight and prevents sunscald. Enclosing the base in a cylinder of hardware cloth keeps hungry rodents at bay.

• Leave glazed ice alone: When freezing rain coats branches in ice, striking them with a broom snaps brittle wood fibers. Let the thaw run its natural course.

Our trees shelter our homes, anchor the landscape, and mark the passage of seasons. Spending an afternoon preparing them for the cold is a quiet act of stewardship—one that ensures they endure winter and return to full life come spring.