Walk through a park after a tree has been cut down, and you’ll notice something that looks harmless but isn’t: a stump sticking out of the ground. The same thing happens in yards. The tree may be gone ...

Stumps. They seem harmless. Just a little piece of wood left after a tree is gone. You might think, “It’s fine, no big deal.” But give it some time, and suddenly it’s a headache. Kids trip over it.

Inside every oak is a bag of mulch waiting to get out. For proof, visit Arlington County's Trades Center, where John Hightower helps trees damaged by last week's storm find their inner woodchip. "This ...