[chumley]

The USDA has just issued the newest revision of the plant hardiness map, which basically shows the annual extreme minimum temperature for a given area so that you know what kind of plants can survive a winter where you live.

If you like maps, there's a lot of information on the USDA website and you can view and download high-resolution maps of individual states or regions, etc.
http://planthardiness.ars.usda.gov/PHZMWeb/

I'm attaching the high-res Arizona map here since it's the one of most interest to HAZ users.

[Jim_H]

Can't really tell where I am, since they don't put my "town" location on the map. It looks like I should be in 0 to +5, but I could be in 0 to -5, or even -5 to -10. Flagstaff is only in -10 to -15, which seems mild considering that it was -19 last January. Well, it is an average minimum extreme.

Since it is related, I'll add that for Flagstaff, this is the first winter season since I moved out here and lived there (8/2006) where it never went (officially) below zero in December or January. If it doesn't do it in February, which seems unlikely given the winter so far, this will probably be a winter without negative temps. I don't think anyone would complain. Well, nuts in Flag would, but they also complain about temps over 70, having a "hot", dry spring with temps in the 80s and 90s and it just not being cold and nasty in general.

[big_load]

Well, it is an average minimum extreme

There has been discussion locally about how people will misinterpret the new data and make costly mistakes. Plants don't live or die according to the average extrema, they live or die according to what they're actually exposed to. Losing a few flowers or other small plantings won't bother most people, but I wouldn't want to bet on trees and shrubs. FWIW, my yard is all native species, except for the lawn, which is an ever-shifting mix of whatever species have managed to survive (about half of which most people would call "weeds").