More than a dozen species of Phlox are native to various ecosystems of California. They are generally uncommon within refined home gardens though. The more popular garden phlox, Phlox paniculata, is native east of Kansas. It naturalizes in some regions, such as the Pacific Northwest. Locally, it might self-sow only where it gets water through summer.
Garden phlox can get as high and wide as three feet. Some modern cultivars should stay a bit more compact. Individual flowers are only about an inch wide, but bloom with many others on dense panicles that are as wide as six inches. This richly fragrant bloom is red, pink, white, pastel orange or pastel purple, and continues for almost a month of summer.
As its potential for naturalization suggests, garden phlox is not particularly demanding. It appreciates good exposure, but can tolerate a bit of partial shade. It enjoys richly organic soil but can survive within soil of mediocre quality if it is not too dense. Regular watering sustains bloom, but established plants can survive with minimal watering after blooming. Propagation by division of large or overgrown plants while dormant through late winter is very easy.