To me, the great thing about these two books is not the first section with all the tree/shrub descriptions and photos, rather it is: "Part II, Selecting Plants for Specific Characteristics or Purposes". Dirr has organized the characteristics in useful ways which give the garden designer much-needed information. Are you looking for a tree with fall color or interesting bark? Are you tired of the same old trees that everyone grows? (Check out the list of 'underutilized' trees.) Is your garden boring in February? Need an evergreen that can tolerate salt? Looking for a vine with a strong fragrance? The answers to all your questions are in this section.
Obviously this book recommendation carries a caveat - it may not be needed in every house. It's a gardening book and if you live in a flat in the city with no patio or rooftop garden, you may survive happily without this - you could, however, substitute a great indoor plant reference. But, you might be find the perfect container shrub for that sunny spot in the bedroom or a tree that will stay small enough for your patio. In other words, don't rule it out without at least flipping through it in the book store.
This concludes our Five Books Every House Needs series. I've enjoyed sharing some of my favorites and would love to hear which books you find invaluable.
Tomorrow we'll be grilling so stop by for a great marinade made with sherry and soy sauce. Right now I think I should check the sherry to make sure it's still good . . . Cheers!