USDA Zones are a general guideline based upon average winter lows and first and last frost dates for a large, general area of the country. Each garden is unique in that there are factors that create micro-climates, both within the landscape and from the surrounding area. These factors can include elevation, mountains, hills, bodies of water, buildings, stands of native trees, open meadows, prevailing winds, etc. A better guide for you would be the zone identified in Sunset Western Garden Book. The authors have gone to great lengths to reclassify general zones, breaking them into sub-zones, based upon local influences. You're in Sunset's zone 9. For a more detailed description, plus suggestions for plants suited to your gardening zone, consult a copy of Sunset Western Garden book, ISBN #0-376-03851-9. |