Years ago, I ordered a perennial from an online catalog simply because the description read, “Looks perfect planted in front of a stone wall.” Our old farmhouse is fronted by a 4-foot-tall wall of cut ...

This long-blooming, easy-to-grow perennial comes in many desirable varieties. But watch out: One is an invasive knotweed. I recently came across an article in my wife’s The English Garden magazine ...