David Neumeyer in Austin, Texas has created, in his words: "an unofficial Henry Mitchell web site, which has, among other things, information about his books, searchable tables of contents, and links to online quotes. The highlight of the site, however, is a set of images taken by Nicholas Weber during visits to Mitchell's Washington garden in 1987."
I learned about the site in one of the forums on GardenWeb (in a message thread that's worth a look itself, as it includes anecdotes of two posters' personal encounters with Henry Mitchell), and was amused to find that the site included a certain "Wisconsin blogger" in its list of links. I love the photos on the site, particularly the one of Henry Mitchell on the site's home page, and the photo of the famous (infamous?) "dog statue" (Henry Mitchell readers of the same degree of obsessive fanhood will know what I'm talking about).