When I mow my lawn, it looks good. But it’s only after I do a pass with a string trimmer, getting in between trees and bushes and edging flower beds, that my yard truly looks finished. That’s why ...

When I bought a home 25 years ago, for the first time, I needed to mow my own yard—an 80-square-foot, postage-stamp-size area. I got a hand-me-down corded string trimmer and started hacking away with ...