Answer: There once was a site with just the information you're looking for, but the site is down. It may or may not be replaced (Time-Life was the owner). In the meantime, I've found a map that's broken down into counties. You'll need 'Acrobat' to read the files (free download at the site). Until the Time-Life Pathfinder site comes back up, maybe this site will help you: http://www.bhglive.com/gardening/mapsindex.html.
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