Plant Problems Demystified
Washington State University's Hortsense Web site presents specific information on about 600 common plant problems in western Washington. It's a tremendously helpful site and one I use often. Topics include problems with turfgrass, ornamentals, small fruits, tree fruits, vegetables, and weeds. The site offers non-chemical management information and a list of registered chemicals for the problem.
Caring for Perennials
Inside Caring for Perennials: What To Do and When To Do It, by Janet Macunovich (Storey, 1997; $18), you'll find a season-by-season guide to creating and maintaining a topflight garden with a minimum of effort. There's general advice for doing preventative maintenance in early spring; mulching, dividing, and moving plants in mid-spring; staking them in late spring; deadheading in midsummer; cutting back and removing them in mid-autumn; and composting in autumn. Chapters on pruning, edging, weeding, watering, and fertilizing round out the book, which focuses on the care and feeding of 130 of the most popular perennials.