Question
Hi there!

I have been trying to identify that climate zone that I live in and I have been getting mixed answers.  I live in Chino Hills Caliifornia, and some websites say my climate zone is 10 and some "western gardening" books say that I am in zone 18.  Please help me.  Thank you!

Answer
Hi Claudia,
Thanx for your question.  I would say you are more in Zone 9b than 10 which is more likely along the coast of Southern California.  You're somewhere in between being somewhat inland near Pomona and Whittier.  The Sunset Western Gardening zone of 18 sounds about right to me but I'm not as familiar with this format as I am with the USDA maps.  I think 10 is too warm for your area and 9b is more accurate.  I hope this helps.
Tom