By the JCS Tree Care team · Led by an ISA Certified Arborist · Updated June 2026
The short version: Oakland County’s mix of mature oaks, maples, and other hardwoods is part of what makes the area’s neighborhoods and lake properties beautiful — and those same big, older trees are the ones most likely to become a hazard. The main risks here are storm damage, internal decay in aging trees, and a handful of diseases and pests that affect local species. Catching trouble early often means a tree can be pruned or treated instead of removed. When a tree is dead, failing, or dangerously located, it should come down before it falls on its own. Not sure where your tree stands? A free on-site assessment by an ISA Certified Arborist will tell you, or call (248) 965-9035.
What makes Oakland County trees prone to trouble
Much of the county’s tree canopy is mature. Large, older trees are exactly the ones that store the most weight, develop the most internal decay, and do the most damage when they fail. Add Michigan’s freeze-thaw winters, summer storms with high winds, and clay-heavy soils that can hold or shed water unevenly, and you get conditions where a stressed or declining tree can fail with little warning. Lake-area and wooded estate lots add another factor: big trees standing close to homes, decks, and shorelines, where there’s little room for error if one comes down.
Common tree hazards to watch for
You don’t need to be an arborist to catch the early warning signs. Look for:
- Deadwood. Bare branches in summer, or large limbs with no leaves, are dead and will eventually fall.
- Cracks and cavities. Vertical cracks in the trunk, or open hollows, point to structural weakness.
- Fungus at the base. Mushrooms or shelf-like growths (conks) on the trunk or roots often signal internal decay.
- A lean — especially a new one. A tree that has started leaning, or shows soil heaving on one side of the base, may be failing at the roots.
- Roots cut or damaged by construction. Recent digging, trenching, or paving near a tree can quietly kill it over a few seasons.
- Branches into the house or power lines. Limbs touching the roof or lines are both a maintenance and a safety issue.
Tree diseases and pests common in this area
A few problems affect species that are common across Oakland County. None of these means automatic removal — but each one is a reason to have the tree looked at.
- Oak wilt. A fungal disease that’s especially aggressive in red oaks. It can spread tree-to-tree through connected roots, and through beetles attracted to fresh cuts. A key prevention step: avoid pruning oaks in spring and early summer (roughly April through July), when the beetles are most active.
- Dutch elm disease. A fungus spread by elm bark beetles that has killed most mature American elms over the decades. Surviving and replanted elms still need watching.
- Spongy moth (formerly known as gypsy moth). In outbreak years, the caterpillars defoliate oaks and other hardwoods. A healthy tree usually survives a season of defoliation, but repeated years, or defoliation on an already-stressed tree, can push it into decline.
- General decay and root rot. Aging trees accumulate internal decay that isn’t visible from outside until a limb or trunk fails.
- Emerald ash borer (historical context). EAB swept through southeast Michigan and effectively wiped out the area’s ash trees years ago — which is why you rarely see a healthy mature ash here anymore. It’s a useful example of how fast a pest can change a local landscape, and a reminder to act early on a declining tree rather than waiting.
When a tree can be saved vs. when it should come down
Plenty of problems are fixable. Deadwood can be pruned out, structural limbs can be reduced, and many diseases can be managed if caught early. A tree is usually a removal candidate when:
- it’s dead or more than about half dead,
- the trunk or major limbs are structurally failing,
- it’s leaning from root failure,
- decay has hollowed a large share of the trunk, or
- it’s positioned where a failure would hit the house, a person, or a power line and can’t be pruned safely.
The honest answer for any specific tree comes from an on-site look. An ISA Certified Arborist can tell you whether yours needs pruning, monitoring, or removal — and not every tree we assess needs to come down.
Storms and seasonal care in Michigan
Summer wind and ice storms are the most common cause of sudden tree failure here. The best protection is proactive: have large or close-to-the-house trees inspected and pruned of deadwood and weak limbs before storm season, not after. If a tree does come down or is left hanging after a storm, treat downed lines as live and keep your distance — that’s emergency work for an insured crew, not a homeowner with a chainsaw. As for timing routine work, late fall through winter (dormancy) is generally the best window for most pruning, with the important exception that oaks should not be pruned in spring or early summer because of oak wilt.
Frequently asked questions
How do I know if a tree on my property is dangerous?
Watch for deadwood, trunk cracks or cavities, fungus at the base, a new lean, and branches into the house or power lines. Any of these is a reason for an on-site assessment by an ISA Certified Arborist.
When should I not prune my oak trees?
Avoid pruning oaks in spring and early summer (roughly April through July), when beetles that spread oak wilt are most active. Late fall and winter are safer.
Are ash trees still a concern in Oakland County?
The area’s ash were largely lost to emerald ash borer years ago, so mature ash are rare here now. The lesson it leaves is to act early on any declining tree rather than waiting.
Can a leaning tree be saved, or does it have to come down?
It depends on why it’s leaning. A long-standing lean a tree grew into can be fine; a new lean with soil movement at the base usually signals root failure and is dangerous. An assessment will tell you which you have.
My tree dropped a big limb in a storm — what should I do?
Stay clear of any downed limbs near power lines and treat lines as live. For hanging limbs or a partially failed tree, call an insured crew rather than attempting it yourself.
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