The label may give some useful information
The Sunset Western Garden Book is a useful guide if you know the zones listed. The Sacramento Valley comprises Sunset zones 8,9, and 14 (Davis is 14). As Farmer Fred says, "this ain't Hawai'i, folks!" If Sunset says a plant grows in the Bay Area zones (15 - 17), we can probably grow it here with some frost-protection measures. Find a microclimate in your yard that traps heat on winter days: south-facing walls, overhangs, enclosed patios. If Sunset lists a plant for the mild parts of Southern California only (Zones 21 - 24), or for Hawai'i (Zones H1, H2) it had better come inside by Hallowe'en and stay until nearly Easter). How much room and sunlight do you have in that spare bedroom? 