Experts warn: These tree problems are easy to miss until it’s too late

• Homeowners should periodically inspect their trees for warning signs.
• Signs of an unhealthy tree include falling bark, abnormal leaves and the presence of fungus or mushrooms.
• Certain tree species, like white pines and Norway maples, are more prone to falling or losing limbs during storms.
• If a tree's health is a concern, an arborist can assess whether it should be pruned, anchored or removed.

Severe weather can turn a seemingly healthy tree into a serious hazard. Arborists say many homeowners don’t realize a tree is in decline until a storm exposes the problem — sometimes with costly or dangerous results.

Board‑certified master arborist Jonathan Quinn, of Hartney Greymont in Needham, MA, says the best defense is simply paying attention.

“You’ve walked by it a dozen times and it was fine,” he said. “Now there’s a sunken area of bark — that raises some flags."

The subtle warning signs homeowners often overlook

Trees rarely fail without giving some kind of signal. According to Quinn, these are the most common red flags:

• bark falling off
• leaves that look unusually small — or unusually large
• fewer leaves than normal
• leaves changing color or dropping earlier than expected
• upright shoots growing at the base or higher up the trunk
• mushrooms growing at the base
• signs of Kretzschmaria deusta fungus, which appears as a thin gray or white crust in spring and matures into a brittle, charcoal‑like black mass

Quinn says about 90% of tree diseases are caused by fungi.

According to Quinn, 90% of all diseases affecting trees are caused by fungi.

“All trees are being attacked by something," he said. "It just depends how healthy they are. Like humans, there’s always bacteria attacking us, but if we're healthy and taking care of ourselves, our immune system fights them off.”

Regular watering and proper mulching can help a tree resist disease and stress.

When a tree should come down — and when it can be saved

Deciding whether to remove a tree depends on more than its appearance. Quinn recommends first assessing what’s around it — nearby homes, cars, play areas or walkways.

Sometimes a tree can be preserved through pruning or anchoring. Other times, removal is the safest option.

“I lean toward preservation, probably more than most other arborists,” Quinn said. “But if it’s keeping you up at night, let’s assess it.”

Homeowners who are unsure should contact a certified arborist or local public works department for an evaluation.

The tree species most likely to fail in storms

Some species are more prone to storm damage than others. Quinn says three types of trees make up the majority of failures during high winds and heavy snow.

White pines are especially vulnerable when they stand alone rather than in groups.

“Any time they’re not in a group, they have the likelihood of falling despite being healthy,” Quinn said.

Norway maples are also known for breaking apart, sometimes without warning. Arborists even have a term for it: “sudden limb drop.”

Dutch and Siberian elms are another pair of species that tend to shed large limbs under stress.

“Usually, they’ll wait until there’s two feet of snow and you’re trying to get out of your driveway,” Quinn said.