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Identifying Hazardous Trees on Your Property

Most of the trees that end up on a house, a truck, or a power line showed warning signs for years. Here's what to look for before the next ice storm.

Every storm I get calls from people who just watched a tree come down on something they owned. Sometimes it's a shed, sometimes a driveway, sometimes a bedroom. And most of the time — not all, but most — the tree was telling them for years that it was going to go. Nobody was looking.

You don't need to be a certified arborist to spot the big warning signs. You just need to know where to look and walk the property once a year with your eyes up.

The big five warning signs

These are what I'm looking at first on any property walk:

“If mushrooms are growing out of your tree, the decay is well established inside. By the time you see the fruiting body, the damage is years old.”

Species-specific problems in New Hampshire

Certain species have predictable failures here. If you have any of these on your property, they deserve a closer look.

White ash. Emerald ash borer has been in New Hampshire since 2013 and is now across most of the state. Infested ash show D-shaped exit holes in the bark, vertical cracks with winding galleries underneath, and a “blonded” look where woodpeckers have chipped off the outer bark hunting grubs. Dead ash becomes dangerously brittle within a year or two — it doesn't rot slowly like other hardwoods, it snaps. If you have ash on your property, assume it's coming down one way or another. Controlled removal now is far cheaper than emergency removal after it's already in the yard.

Eastern hemlock. Hemlock woolly adelgid — the white cottony clumps on the underside of branches — has reached most of NH. Infested hemlocks thin from the bottom up and die over five to ten years. A hemlock with a thinning crown near a house or driveway is on borrowed time.

White pine. NH's tallest tree is also the one most prone to wind-throw. White pine has a relatively shallow root system and grows faster than it can build strong wood. Pines that have always grown in a crowded stand and then suddenly have one side exposed — after a neighbor's clearing, a construction project, or another blow-down — are at high risk in the next storm. Look for trees with crowns that look out of balance with their trunks.

Paper and yellow birch clumps. Birches are short-lived (60 to 80 years) and tend to decline together. When one stem of a multi-stem birch dies, the others usually follow within a few seasons. A birch clump with one dead stem is about to become a birch clump with three dead stems.

When to walk the property

Early spring — just after the snow melts, before the leaves come out — is the best single window of the year for a tree walk.

A second walk in late summer catches anything that declined during the season — especially ash, which can go from green-looking to dead within a single year.

DIY vs. calling someone

Plenty of small tree work is reasonable for a homeowner with a chainsaw and experience. A low branch, a sapling, a small standing-dead tree in an open area — those are all manageable with common sense.

The line I draw is here. Call a professional if:

Chainsaw accidents and tree-removal injuries are some of the most common serious home injuries in rural New England. Every year. A removal that costs a few hundred dollars done right is a lot cheaper than an ER visit or a totaled car.

What we do

I walk properties at no cost. We look at what's there, flag anything that's actively dangerous, and talk through what can wait and what shouldn't. If something needs to come down, I give a written estimate the same day. No pressure, no upsell on trees that are fine.

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