Santa Barbara or Santa Cruz hands-on or long-term eyewitness info is very useful too!
descriptions & pics of these look good for a Primula for the coast:
P vulgaris, P polyanthus (I've seen English Primroses or Polyanthas only as common winter annual, so have no idea how long lived in a foggy coastal climate) "Garryarde Guinevere" white with dark leaves could be good, but seems unavail. P 'Cowichan' cvs P juliae (Juliana, Pruhonicensis, pruhoniciana) Fill? Scattered individual flowers? P obconica, only the non-irritating haired cvs. (But appears obconica flowers are in clusters -- more prone to (fortunately rare) vandal damage.)
Cultural considerations: Shade lover high or shade tolerance. No/less division required. longer lived Evergreen (assuming evergreen Primroses don't become too ugly in the warm season.) Multi stemmed or individual flowers is best. Single stem with "bunch" of flowers is more vandalism prone. tall or otherwise able to hold it's own among low smothering shady covers such as Soleirolia Soleirolii (Baby's Tears) or Herniaria (Rupturewort). Maybe the Primrose itself will fill, clumping, rhizomes. Some sense of how water dependent the plant is would help me too. :) I have plenty of control over soil, as these will be in large planters/containers.
References: web, Sunset Garden Book, Phillips & Rix, various others.