Reviews Understanding Perennials: A New Look at an Old Favorite by William Cullina Share this: Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print By Science News July 17, 2009 at 10:08 am An intimate portrait of perennials aims to give a deeper understanding of these garden standbys.Houghton Mifflin Harcourt, 2009, 247 p., $40. Understanding Perennials: A New Look at an Old Favorite by William Cullina