Mettee suggests buyers do a true survey of property lines so they know what they're getting upfront. That will run you at least $1,000 -- possibly several thousand dollars, depending on the size of the property, he said.

"I've heard individuals say many a time, they thought that their property went to such-and-such a place and never really had a survey to determine that, only to find out years later that they didn't actually acquire what they thought they were acquiring," said Mettee, who gets a number of calls from homeowners disputing property lines with neighbors.

You can go to your local land records office to see the official word on your property. But unless you have professional training, Mettee doubts you'll be able to translate it into useful information.

If the tree that needs trimming might be sitting in public right-of-way, you have other places to turn. In Baltimore County, for instance, you'll want to call the Bureau of Highways, 410-887-3560 , which will make a determination. Should the tree be in the right-of-way, the bureau will also decide whether to trim (or remove).

The county doesn't charge for the maintenance, but you will have to pay a $25 work-order application fee, said David F. Fidler, a spokesman for the county Department of Public Works.

You also might find yourself with neighbor issues, never mind that the tree is county responsibility.

"We've had so much interest in the last year or two about trees -- for various reasons, it's become a hot topic in the county," Fidler said. "You may ask to have it taken down, and your neighbors may love that tree. ... This has sparked a good deal of controversy."