Buy the hardback version because this book will get your fingers walking frequently. The first book I reach for and often the only one I need. For me it is particularly helpful for desert plant selection and descriptions, but any western gardner will find a wealth of information. There are 24 sections on plant selection for specific needs and situations including shade, color, site, fragrance, native, season, foliage, compatibility, birds/butterflies, and others. Color plates accompany many of the selections along with growing requirments. Double index of gardening topics and common/scientific names. Excellent sketches of 6000 individual plants with similar family members. Much peripheral info such as how to read scientific names, pest problems/solutions, resourses, fine tuning of climatic zones. This is a fine reference book. An excellent source for new and experienced gardners.