Tree problems

Learn the difference between a sick tree and a dangerous tree. They overlap but they are not the same. The International Society of Arboriculture describes decline symptoms including "smaller and fewer leaves, dieback in the crown of the tree, and premature fall color." Those tell you the tree is struggling. They do not tell you it is about to fall — plenty of struggling trees stand for another decade.

Danger signs are mechanical. Fungal fruiting bodies at the base often mean root or butt decay you cannot see. A lean with cracked or lifted soil on the opposite side means the root plate is moving. Vertical trunk cracks, large cavities, and included bark at a major fork are structural defects. Large deadwood over anything you care about is a fall hazard independent of the tree's overall health.

Construction damage is the slow killer people never connect. ISA lists physical injury to trunk and crown, soil compaction in the root zone, and severed or smothered roots as the mechanisms. A tree that was fine before a driveway, addition or trench went in can decline for years afterward, and by the time the crown thins the roots are long gone.

The right response to most of this is a tree risk assessment, not immediate removal. ISA maintains a Tree Risk Assessment Qualification, and an arborist with that credential is assessing likelihood of failure, likelihood of hitting a target, and consequences — a structured judgment, not a guess. If a company arrives, glances at the tree, and quotes removal in 90 seconds, get a second opinion.

How to choose

Mushrooms at the base are a same-week call

Fungal fruiting bodies on the trunk or root flare often mean decay in the part of the tree holding it up. You cannot assess this from the outside.

Watch for a lean that changed

Trees that grew leaning are often fine. A tree that started leaning recently, or has cracked soil on the uphill side, is a different problem entirely.

Ask for a TRAQ-qualified assessor for a big decision

ISA offers a Tree Risk Assessment Qualification. If someone is telling you to spend thousands removing a mature tree, this is who you want making that call.

Look up, in winter

Bare-branch season is when structural defects, deadwood and cracks are actually visible. Do a slow walk-around of every large tree once a year.

Protect roots during construction, before it starts

Fencing off the root zone before equipment arrives costs almost nothing. Reversing compaction and severed roots afterward mostly does not work.