Dry to moist open woods and thickets from lowlands to middle elevations. More common east of the Cascades, but also in the drier forests of the Puget Lowlands.
Coarse-textured well-drained soils.
Tolerates poorer soils because of its nitrogen-fixing ability.
Prefers neutral to mildly alkaline soils.
Moist to dry soils. Drought tolerant.
Full sun to light shade.
Climax in semi-open forests. Pioneer on disturbed sites.
Scattered throughout Coastal Douglas-fir zone. Occurs with Garry oak on limestone soils. More common in the British Columbia Interior where it is widely distributed.