Specimen plants are those that transform your landscape from one that merely exists to one that grabs everyone's attention. We discuss our favorites, those that have been little more than fads, and those that have truly stood the test of time, like the oak tree that Olympic champion Cornelius Johnson planted outside his Los Angeles home. Plus, we talk spring emergence of bulbs and Mr. Mustard Ural false-spirea, answer listener questions on lilacs, and the latest on Central Park's escaped owl, Flaco.