Showerthought: your 'tree is dying' call is usually just mulch piled 8 inches up the trunk
I've been called out to look at 'dying' maples in Cincinnati three times this month and every time it's volcano mulch smothering the root flare. Pull the mulch back, find the flare, and tell me I'm wrong.
I read somewhere that the mulch thing got way worse after landscapers started using those big blower trucks that just pile it on. Saw a study too that girdling roots from deep mulch can take like 10 years to actually kill the tree, so by the time it looks bad the damage is old. How deep are you usually finding the flare buried out there?