An encyclopedia of Japanese plants supplements discussion on Japanese landscape design as well as examples of and techniques for creating Japanese gardens
Well researched book covering the history and evolution of Japanese gardening, the most important extant examples, the common misconceptions about it in the West, the important aesthetic principles, the practical ways to create gardens in the US, the plant encyclopedia, etc. For an amateur, I can't think of anything more.
While the publication date on this book made me think it might be outdated, I found the opposite to be true. The photographs are beautiful, and the basic concepts are illustrated in an approchable and informative way. In fact, I have already started implementing some of the pruning and grouping techniques in my own gardens. I'm very glad I picked up this book.