Dead or Dying Tree Warning Signs (Including Emerald Ash Borer in PA)

Most trees that fall on houses gave warning first. You don't need to be an arborist to spot the obvious red flags, and catching them early usually means a cheaper, safer, scheduled removal rather than an emergency one. Walk around your trees in daylight, ideally twice a year: once in summer with leaves on, and once in winter when the structure is easy to see.

The crown (top of the tree)

Dead branches with no leaves in summer, especially large ones over the house, driveway or play areas.
Thinning from the top down (dieback). Leaves smaller or sparser than neighboring trees of the same kind.
Early fall color or leaves browning in midsummer.
Hangers: broken limbs caught in the canopy. These can drop at any time and should be removed promptly.

The trunk

Cracks and splits, especially vertical cracks or a split running down from a fork.
Weak forks: two co-dominant trunks with a tight V and bark pinched between them are prone to splitting.
Cavities and decay: holes, soft or crumbly wood, or hollow sound when tapped.
Missing bark or bark falling off in sheets.
Mushrooms or conks on the trunk or at the base, a sign of internal decay.

The International Society of Arboriculture's homeowner guidance lists these same defects (dead wood, cracks, decay, weak branch unions, root problems, poor architecture) as the key signs of tree risk (ISA TreesAreGood, Recognizing Tree Risk).

The roots and base

New lean, or soil heaving and cracking on the side opposite the lean, especially after heavy rain.
Root damage from trenching, driveway or sidewalk work, or grade changes within the root zone, common in older Scranton neighborhoods where utilities and sidewalks get redone.
Fungi growing from roots or the root flare.

Emerald ash borer: why ash trees are a special case

Emerald ash borer (EAB) is an invasive beetle now found throughout Pennsylvania, and it kills nearly all untreated ash trees, usually within a few years of infestation (PA DCNR: emerald ash borer). Ash is common in NEPA yards, along streets and on wooded lot edges, so this is one of the most common reasons people here need removals.

Signs of EAB

Thinning and dieback starting at the top of the crown.
D-shaped exit holes about 1/8 inch across in the bark.
Vertical bark splits, with S-shaped tunnels (galleries) underneath.
Heavy woodpecker activity that strips patches of outer bark ("blonding").
Sprouts growing from the lower trunk.

Treat or remove?

Healthy, valuable ash trees with little canopy loss can sometimes be protected with insecticide treatments by a certified applicator. Once a large share of the canopy is gone, removal is usually the realistic option (PA DCNR: emerald ash borer). Dead ash dries out and becomes brittle quickly, so it's harder and riskier to climb, and removal often costs more the longer you wait.

Other local pests worth knowing

Lackawanna and Luzerne counties are in Pennsylvania's spotted lanternfly quarantine. Lanternflies favor tree of heaven, an invasive tree common along alleys and lot edges (Penn State Extension: spotted lanternfly). Removing tree of heaven is a common request.

When to call a pro

Any defect on a tree big enough to reach the house, a car, a road or a neighbor's property if it fell.
A sudden new lean.
Large dead limbs over places people spend time.
Any tree near power lines. Don't work near lines yourself.

Removal might not be needed. Deadwood pruning or crown reduction can fix many problems; see trimming vs. removal. Storm Limb Help can connect you with an independent local tree service for an assessment: call (570) 565-1102.

Quick answers

How can I tell if my tree is dying?

Look for dead branches in summer, top-down thinning, cracks, cavities, mushrooms on the trunk or roots, bark falling off, and a new lean.

What are signs of emerald ash borer?

Top-down crown thinning, D-shaped exit holes about 1/8 inch wide, vertical bark splits, heavy woodpecker damage, and sprouts on the lower trunk of ash trees.

Can an ash tree with emerald ash borer be saved?

Sometimes, if it is still healthy and treated by a certified applicator. Heavily declined ash trees usually need removal.

More guides

Last reviewed 2026-10-26. General information only; sources linked inline.