Post-Winter Tree Damage: What to Look For

Every March, I walk my own property and do the same inspection I recommend to every customer. Massachusetts winters are brutal on trees — ice storms, heavy snow, freeze-thaw cycles, and wind all take their toll. The problem is that a lot of winter damage is not obvious until you look for it, and once spring growth kicks in, leaves and new shoots can mask problems that are getting worse underneath. Here is what to look for before spring hides the evidence. I am Keith McDonald, and I have been assessing winter tree damage across Billerica and Middlesex County for over 30 years.

Ice Storm Damage

Ice is the number one tree killer in Massachusetts winters. A quarter inch of ice on every branch and twig adds hundreds of pounds of weight to a mature tree. Here is what ice does and what to look for in March:

Split forks

When ice loads unevenly on a tree with a V-shaped fork (called included bark), the two leaders can split apart. This is the most common ice damage we see, and it happens most often on maples and birches. Walk around each tree and look up at every major fork. If you see a crack running down between two main stems, the tree has a structural failure. Sometimes the split is obvious — you can see daylight between the two halves. Other times it is a hairline crack that will widen with the next storm.

Broken leaders

The leader is the main central stem of the tree. When a leader snaps from ice loading, the tree loses its structural backbone. A broken leader usually means the tree is a candidate for removal rather than repair. The remaining canopy is off-balance and the tree will never recover its natural shape. We see broken leaders on tall white pines and red maples more than any other species in our area.

Hanging branches (widowmakers)

Broken branches that are caught in the canopy instead of falling to the ground are extremely dangerous. They can drop at any time — a gust of wind, a warm day that loosens ice, or just gravity. If you see a broken branch lodged in your tree, do not walk under it and do not try to pull it down yourself. Call a professional. We respond to widowmaker calls as a priority because they are unpredictable. Learn more about our emergency tree service.

Snow Loading Damage

Heavy, wet snow — the kind Massachusetts gets in March nor'easters — does different damage than ice. Snow bends rather than snaps, but the results can still be permanent.

Evergreen damage

Arborvitae, hemlocks, and white pines are the most common victims of snow loading. Heavy wet snow pushes branches down and out. Multi-stemmed arborvitae that were screening your backyard all winter may now be splayed open permanently. Hemlocks with lower branches can be bent to the ground. White pines with long horizontal limbs can have branches snap from the weight. Look for branches that are hanging lower than they were in the fall or that have a sharp bend rather than a natural curve.

Multi-stemmed tree splits

Trees with multiple trunks growing from the same base — common in birch, maple, and ornamental cherry — are vulnerable to splitting from snow weight. The snow loads one side more than the other, and the stems pull apart. Check every multi-stemmed tree on your property for new gaps between the trunks.

Young trees with permanent lean

Newly planted trees or young trees under 15 feet tall can be pushed into a permanent lean by repeated snow loading. If the lean is slight and the root plate is intact, staking can sometimes correct it. If the lean is more than 15 degrees and you can see soil cracking on one side of the base, the tree may need to be replaced.

Frost Cracks

Frost cracks are vertical splits in the trunk, usually on the south or southwest-facing side. They happen when winter sun warms the bark during the day, causing the outer wood to expand, and then a sudden drop in temperature at night freezes it rapidly. The outer layers contract faster than the inner wood, and the trunk splits.

Frost cracks are most common on thin-barked species: maples (especially red and sugar maples), birches, London plane trees, and young oaks. You will see a vertical line running up the trunk, sometimes with raised edges where the tree has tried to heal over previous cracks. In towns like Chelmsford, Westford, and Carlisle, where temperature swings between sunny winter days and cold nights can be 40 degrees or more, frost cracks are common.

The good news: frost cracks are usually not fatal. The tree walls off the damaged area and continues growing. The bad news: each crack opens the tree to decay organisms that work inward over years. A tree with repeated frost cracks on the same spot is slowly developing internal decay. Monitor these trees annually and have them assessed if you see fungal growth near the crack.

Root Heaving and Soil Movement

This one is easy to miss but potentially the most dangerous. Freeze-thaw cycles push the entire root plate upward, especially in clay soils and areas with poor drainage. Look for:

• Cracked or raised soil on one side of the tree. If the ground looks like it has been pushed up in an arc around part of the base, the root plate has heaved.
• Newly exposed roots. Roots that were underground last fall are now visible at the surface.
• A new lean that was not there before winter. Compare to how the tree looked in October. Even 2-3 degrees of new lean is significant.
• Gaps between the root flare and the soil. If you can see air space between the trunk base and the ground on one side, the root plate has lifted.

Root heaving is particularly dangerous for shallow-rooted species like white pines, Norway spruces, and silver maples. We see it regularly in Tewksbury, Carlisle, and Wilmington where clay soils and tall trees are a common combination. A tree with significant root heaving can topple in the next windstorm. If you see any of these signs, get a professional assessment before the spring storms arrive. Read our guide on warning signs a tree needs removal for more on root plate failure.

When Damage Means Removal vs. Pruning

Not all winter damage means the tree has to come down. Here is how we think about it:

Pruning can fix:

• Broken branches up to about 4 inches in diameter, as long as the remaining branch structure is healthy
• Minor crown damage where less than 25 percent of the canopy is affected
• Single limb failures where the rest of the tree is structurally sound
• Light thinning to reduce weight on ice-damaged branches

Removal is the right call when:

• The trunk is split. A split trunk cannot be repaired. Cabling can sometimes stabilize a minor fork split, but a trunk split is a structural failure.
• More than 50 percent of the crown is lost. The tree cannot sustain itself with less than half its canopy and will decline over the next few years anyway.
• The root plate has heaved or failed. A tree with a compromised root system is a falling hazard that pruning cannot fix.
• The tree has developed a significant structural lean. A straight tree that is now leaning 10+ degrees has likely had root failure.

For a detailed comparison, read our guide on tree pruning vs. tree removal.

What to Do Next

Walk your property now, in March or early April, before leaves fill in and obscure the damage. Take your time. Look at every tree from multiple angles. Look up into the canopy for hanging branches. Look at the trunk for cracks. Look at the ground for heaving. If something looks wrong, it probably is.

Do not touch hanging branches yourself. A broken branch lodged in a tree is under tension. When it releases, it can snap in an unpredictable direction. Leave widowmakers to professionals with the right equipment and training.

For a proactive approach to spring tree work, check out our Spring Tree Care Checklist for Massachusetts and our Spring Tree Removal landing page.

Schedule a Free Winter Damage Assessment

McDonald Tree Service provides free post-winter tree assessments across 18 towns in Middlesex County. I will walk your property with you, look at every tree, and give you an honest evaluation of what needs attention and what can wait. No charge, no obligation.

We serve Billerica, Chelmsford, Lowell, Tewksbury, Wilmington, Burlington, Bedford, Carlisle, Dracut, Westford, Andover, Woburn, Lexington, Concord, Lincoln, Winchester, Acton, and Waltham.

Call (978) 375-2272 to schedule your assessment. The sooner you catch winter damage, the safer your property will be when spring storms roll through.