"The editors of Sunset-the West's most trusted source of gardening information for more than 80 years-have completely redesigned and updated The Western Garden Book in this new 2012 Ninth Edition. This edition includes a fresh new look, thousands of color photographs, fresh illustrations, and an easy-to-follow format."--Publisher.
In comparison, I subsequently found a copy of the 8th (2007) edition, and decided not to keep it. It is not nearly as user-friendly. Sections in what were previously landscaping designs for specific situations are so embellished with glossy photographs and plant cultivar close-ups as to render this information less detailed. As well, opening spreads are glossy postcard layouts, reminiscent of coffee table books emphasizing pretty views. Rather than this edition being a solid reference, these additions have reduced the book to a more general overview. So I'm preferentially keeping the 1986 edition (and my earliest Western Garden edition from the 1970's).