This strikes a happy medium between Marion Dulles' Greenhouse Gardening Round the Year (definitely geared to the beginner) and the thoroughly professional Complete Book of Greenhouse Gardening by the Northens. Here are the hows, wheres and whens for both expert and amateur who is beyond the starter stage. There is very useful information on types of greenhouses, Locale, choice of equipment as well as procedures and techniques. It is as up to date as Gibberellic Acic and as down to earth as step by step how tos for the neophyte. There is the best material I have found on auxiliary growing areas, from framen to lath houses. Specific sections deal with material- from specialties to the usual run of greenhouse flowers and vegetables. Mr. Potter is editor of the Oregon Flower Grower, and author of numerous books on gardening topics, within his field.