wrote:
http://arborday.org/media/zones.cfm


Extreme winter lows are not the only climate factor to be considered
when choosing plants. Summer highs are also significant, as are such
things as how long the lows and highs last, the general amount of
moisture in the air, the wind patterns, etc. That's why I still refer
to Sunset zones.

Fuschias are hardy enough for where I live. I can't grow them because
my summers are too hot and dry.


--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/