In the Santa Monica Mountains, coastal sage scrub occurs on drier sites and lower elevations than chaparral, especially on coastal south-facing slopes. Coastal sage scrub is also common in inland areas of the Simi Hills within the park boundary. Often occurring in recently eroded areas, this community plays an important role in soil stabilization. Many of its characteristic plants produce soil-holding, fiberous shallow roots. Soils underlying coastal sage scrub tend to be low in nutrients and subject to rapid erosion.
The coastal sage scrub community has been referred to "chaparral" since soft-leaved, grayish green, aromatic shrubs characterize the widely spaced vegetation. Characteristic plants include purple sage (Salvia leucophylla), California sagebrush (Artemesia californica), coast goldenbush (Haplopappus venetus), coastal buckwheat (Eriogonum cinereum), laurel sumac (Malosma laurina), and lemonadebery (Rhus integrifolia).
Many species in this community, particularly the sages, are summer or drought deciduous, dropping larger leaves during mid-summer to conserve moisture.
Good examples of coastal sage scrub can be found at the mouth of Zuma Canyon and in coastal Point Mugu State Park.