In BC occurs primarily within the rain shadow of the Olympic Mountains and the Vancouver Island ranges. Grows at low elevations on various sites and soil types. In BC ranges from Comox through the Gulf Islands to Greater Victoria. Isolated occurrence in the lower Fraser Canyon near Yale.
Rocky outcrops to deep, rich, well-drained soils. Grows best in the latter.
Moist to dry.
Shade tolerant as young seedlings, becoming shade intolerant with age.
Climax species on open, xeric sites. Tends to be out-competed on mesic sites unless maintained by frequent disturbance (i.e. fire).
Characteristic species of Garry oak ecosystems.