When to Remove a Tree: 7 Warning Signs Every Homeowner Should Know

Not every tree needs to come down. Healthy trees add value to your property, provide shade, and look great. But a tree that is dying, structurally compromised, or growing into a place it should not be is a liability, not an asset. The trick is knowing the difference.

I am Keith McDonald, owner of McDonald Tree Service in Billerica, MA. We have been assessing trees across Tewksbury, Chelmsford, and the rest of Middlesex County since 1995. Here are the seven warning signs that tell us a tree needs to come down.

1. More Than 50% of the Crown Is Dead or Dying

Look up. If more than half the canopy has bare branches while the rest of the tree has leaves, the tree is in serious decline. A few dead branches are normal. Half the crown being dead is not.

This is especially common with ash trees across Massachusetts. The emerald ash borer (Agrilus planipennis) has devastated ash populations in Billerica, Tewksbury, Chelmsford, and every other town in our service area. The insect was first confirmed in Massachusetts in 2012, and by 2026 it has killed the majority of untreated ash trees in Middlesex County. If you have an ash tree and the top third is bare, it is almost certainly infested and needs to come down before it drops large dead limbs.

What to look for: Bare branches in the upper canopy during the growing season (June through September). Leaves that are significantly smaller than normal. Early leaf drop in August while other trees are still green. Bark falling off large branches.

2. Large Cavities or Hollows in the Trunk

A small cavity is not necessarily a death sentence for a tree. Trees can compartmentalize decay and wall it off internally. But when a cavity is large enough to fit your fist inside, or when you can see daylight through the trunk, the structural integrity is compromised.

We see this often with old sugar maples in Lexington and Bedford. Beautiful trees that have been growing for 80 or 100 years, but the interior is hollow. They look fine until a nor'easter puts 40 mph winds on that canopy, and then 60 feet of hollow maple is on your roof.

The rule of thumb: If the cavity or combined cavities cover more than one-third of the trunk's circumference, the tree is a removal candidate. If you can see through the trunk or there is soft, punky wood around the opening, do not wait.

3. Root Damage or Heaving

Roots are the foundation. When they are damaged, cut, or decaying, the whole tree is at risk of toppling. Root problems are tricky because you often cannot see them until it is too late.

Signs of root problems include:

• Soil heaving or cracking on one side of the tree, which indicates the root plate is lifting
• Visible roots that are severed, decaying, or covered in fungal growth
• A sudden lean that was not there last year
• Construction or excavation work that cut through major roots within the last 1 to 3 years (the effects of root damage often take 2 to 5 years to show in the canopy)
• The tree rocking noticeably when pushed or in moderate 20 mph wind

In Dracut and Lowell, we see root problems on trees near the Merrimack River where bank erosion undermines root systems. In Tewksbury, the saturated soil around Long Pond and Silver Lake weakens root hold, especially for tall white pines that act like sails in the wind.

4. A Significant Lean That Is Getting Worse

Some trees grow with a natural lean and are perfectly stable for decades. The problem is when a previously straight tree starts leaning, or when an existing lean is getting more pronounced year over year.

A tree that has suddenly developed a lean, especially after a storm or heavy rain, is a genuine emergency. It means the root system is failing on one side. That tree can come down without warning.

How to tell the difference: A natural lean has a curved trunk that compensates over the tree's lifetime. The trunk bows to shift the center of gravity back over the root zone. A dangerous lean has a straight trunk that tilts from the base, often with soil heaving on the opposite side. If you have to tilt your head to look at it and there is cracked soil on one side, call us.

White pines are the biggest offenders in our area. They grow tall and straight for decades, then one ice storm loads up the canopy unevenly and they develop a lean that does not correct. We remove leaning pines in Tewksbury and Wilmington every week during storm season.

5. Storm Damage With a Split Trunk

Massachusetts gets hit with nor'easters, ice storms, microbursts, and the occasional hurricane remnant. Storm damage is part of life here. A tree that loses a few branches in a storm usually recovers fine with proper pruning. A tree that has a split trunk does not.

A split trunk means the tree's main structural column is compromised. Even if the tree is still standing and still has green leaves, a trunk split will only get worse. Water gets in, decay starts, and the next storm finishes the job, usually at the worst possible time.

The test: If you can see a crack running down the main trunk, or if the tree split at a major fork and one side is hanging or leaning, that tree needs to come down. Do not wait for it to heal. Trees do not heal trunk splits. The wood does not knit back together. It just gets weaker as decay organisms move in.

6. Fungal Fruiting Bodies (Mushrooms on the Trunk or Base)

Mushrooms growing out of the ground near a tree are usually fine. They are breaking down leaf litter and organic material, and that is normal forest ecology. Mushrooms growing directly out of the trunk or the root flare of a tree are a very different story.

Fungal fruiting bodies on the trunk or base mean the interior wood is decaying. By the time you see mushrooms on the outside, the decay inside is extensive, often affecting 60 percent or more of the wood's structural capacity. Common culprits in Massachusetts include:

• Artist's conk (Ganoderma applanatum): Flat, shelf-like brackets on the trunk, gray-brown on top and white underneath. Indicates advanced heart rot in the trunk. Common on red oaks and sugar maples.
• Honey mushroom (Armillaria mellea): Clusters of yellowish-brown mushrooms at the base in fall. Attacks the root system and lower trunk. Extremely common on red oaks in our area and one of the most aggressive tree pathogens in New England.
• Chicken of the woods (Laetiporus sulphureus): Bright orange and yellow shelves on the trunk. Indicates internal brown rot in oaks, maples, and other hardwoods.

If you see any of these on a large tree near your house, call us for an assessment. We see this regularly on older red oaks throughout Andover, Burlington, and Chelmsford. Sometimes the tree can stay for a few more years with monitoring. Sometimes it needs to come down this week. That is a judgment call that requires looking at the whole picture.

7. The Tree Is Causing Structural Problems

Trees and buildings do not always coexist. When a tree's root system is cracking your foundation, lifting your driveway, or invading your sewer line, you have a conflict that pruning will not fix.

Similarly, when a large tree's canopy is growing directly over your roof and dropping limbs with every storm, or when the trunk is so close to the house that it is rubbing against the siding, removal may be the only practical solution.

Common structure conflicts we see in our service area:

• Norway maple and silver maple roots cracking foundations and heaving walkways (these species have notoriously aggressive surface root systems)
• Roots invading sewer lines or septic systems, especially common with willows and silver maples
• Canopy overhanging the roof by 15 feet or more, creating a constant debris and damage risk during storms
• Trunk within 5 feet of the house and still growing, eventually pushing against siding or the foundation
• Trees that block solar panels, which is increasingly common in Burlington and Lexington as more homeowners install solar

When Pruning Might Save the Tree

Not everything on this list is an automatic removal. A tree with 30 percent crown dieback might recover with proper pruning and care. A tree with a small cavity can often be monitored for years. If the lean is slight and stable, pruning to reduce weight on the leaning side can buy time.

The key is getting a professional assessment before making the decision. We will tell you honestly whether a tree can be saved or whether it needs to come down. We do not push removals when pruning will do the job. Repeat customers are more valuable to us than one big removal bill.

For a deeper look at the pruning vs. removal decision, read our Tree Pruning vs. Tree Removal guide.

What to Do Next

If you see any of these warning signs on a tree near your home, do not ignore them. A dead or compromised tree is a liability. It can damage your house, your car, your neighbor's property, or injure someone. Insurance may not cover damage from a tree you knew was hazardous and chose not to address.

Call McDonald Tree Service at (978) 375-2272 for a free assessment. We will come out, look at the tree, and give you an honest recommendation. We serve Billerica, Chelmsford, Lowell, Tewksbury, Wilmington, Burlington, Bedford, Carlisle, Dracut, Westford, Andover, Woburn, and Lexington.