>Bob posted a link to a photograph of a USDA climate zone map from 1936. Were the temperature ranges for each zone the same then as they are now? It was Rick’s link. It doesn’t seem to matter what the ranges were. Much of the northeastern US is shown in the same zone as some of the more frigid parts of Colorado. (Extreme northwestern Colorado.) If that were true, then much of New York, northern New Jersey, and western Connecticut would be devoid of much of any vegetation, because of the continual drops in temperature to –50F (-45.5C) and below. We probably would have read about that at one time or another. Bob Nold Denver, Colorado, USA _______________________________________________ pbs mailing list pbs@mailman1.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/