This is an article that indicates “Japanese boxwood, which grows in USDA zones 3 through 9 depending on the cultivar”. Others will list zone 6 through 9. I have them as a low hedge in the front yard. The squirrels would go around them, not going through under, like on neighbors’ sites with other native bushes. They would avoid rose bushes also, so I planed a lot of roses recently to discourage them from climbing the walls and fences. Both can be big and evergreen in Socal. Not sure how it will be in your area.