John Bryan, Jaime, Roger, Lee, et al., To answer John's original question directly, yes, I believe that the USDA cold zones are useful and should be retained. What to add to them is the problem. The American Hort. Society heat zones would be a good start. Then add in maps of annual rainfall. That is a start. Nothing will make decisions about growing 100% foolproof for novice gardeners, and nothing will keep old hands from experimenting. Besides nighttime minimum temperatures for the AHS heat zones, one needs to add local effects for urban islands of heat. I live 25 miles from the center of a medium-large sized urban agglomeration. We are routinely 2 to 5 degrees F cooler than in the city, summer and winter. But you should hurry John, because it looks like the climate is changing and the existing tables will become obsolete in a few more years. Spring is coming a week to 10 days earlier now than it did 25 years ago. Jim Shields in central Indiana USDA cold zone 5 AHS heat zone 6 40 inches of precipitation per year At 09:49 AM 10/28/2005 +0200, you wrote: >Ahh, Roger, > >hard but true words! We are always seeking a simple solution to the >complexities of life. I didn't realize that the Arnold Arboretum (a truly >wonderful place to visit!) was behind the original Zones. >......... >In the end, Zones are nothing but a guideline and one must not only know his >local conditions, but understand them as well! > >Jamie Vande >Cologne >Germany ************************************************* Jim Shields USDA Zone 5 Shields Gardens, Ltd. P.O. Box 92 WWW: http://www.shieldsgardens.com/ Westfield, Indiana 46074, USA Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA