Perennials are the most challenging and rewarding of all garden plants, and most gardeners need all the help they can get to grow them well. Perennials emerge from the ground in early spring, grow to full height, bloom, bear fruit, and then disappear with the first frost, only to do the same thing the following year and again the next. Add this to the fact that for the first year or two, perennials don't do much above the ground (they are growing their root structure), but after that they burst forth with amazingly vigorous growth, and you get an idea of the pleasures and tribulations of perennial gardening. The rewards, however, are rich: a wide array of flower forms and colors, structure and leaf, an ever-changing mid-level tapestry in the garden, plus a celebration of seasonal change. Few gardeners can resist perennials, but how to grow them better and more effortlessly? Readers can count on Rodale books to be practical and detailed and to advocate organic gardening. While Rodale's Illustrated Encyclopedia of Perennials does give information, as you would expect from Rodale, on soil building, climate, propagation and nontoxic pest and disease control, its emphasis is on design. The advice is down-to-earth, as in a sidebar entitled "Evergreen Perennials: Myth or Reality?" that points out that although some perennials are touted as evergreen, and do keep their leaves through the winter (such as Epimedium, Ajuga, and Bergenia), they are often so tattered by winter storms that they shouldn't be counted on to beautify the garden off-season. Though packed with all sorts of useful information, the meat of the book is the encyclopedia of perennials. From acanthus to yucca, each comes with a color photo, cultural and cultivar information, as well as suggestions on use. Rodale's Illustrated Encyclopedia of Perennials is an invaluable reference for anyone interested in these rewarding, though somewhat demanding, plants. --Valerie Easton