We recommend using a "Plant-Finder" search engine to find the best plants for the your site. Plant Finders can take characteristics into account such as drought tolerance, soil type, size, sun exposure and cold-hardiness. California Native Plants for your specific climate can be found here at Las Pilitas. Plant Finder for Water-Wise Plants in San Luis Obipo, UC Davis Arboretum All-Stars, Sunset Plant Finder. Need help finding the perfect tree? Use Cal Poly Tree Select.
Afraid you will plant the wrong thing.. we recommend to periodically check out Plant Right for a list plants that are invasive in the state of California!