I think that might be wrong, Sue. The temperature in Sebastopol has fallen below 20 degrees only three times in the last 50 years. Every other map puts Sebastopol in zone 9a, and some of the newer data assign us to 9b. This one's very strict if it puts us in zone 8 on the basis of three morning temperature readings of 19, 17, and 14 degrees in 50 years.
