Woody plants are indeterminate growers, i..e., they do not stop growing, unless dormant, until they die. The garden center lables really, if ever, suggest as much, instead listing a size (height and often width), and using the term mature, that most people interpret as being a maximum. NOT! The specimen is in the photo is a spectacular (12 x 30) weeping cherry about fifty-years-old (notice my daughter in the lower left). Unfortunately, people often plant this species, as well as many other woody species, too close to a building or passage way making it impossible for the specimen to have the space to attain this older age magnificence.