Habit: fast growing, perennial with a woody base, forming a large round or tree-shaped shrub. It has numerous branches with green to gray green leaves that are palmately divided with 5-12 leaflets sparsely covered in silky white hairs. Just above the foliage the inflorescence is a long racemes (spikes) of loosely arranged yellow pea like flowers having a sweet fragrance. The fruit is a hairy pod with flattened mottled brown seeds. Tree lupine blooms in late spring to early summer.
Ecology: tree lupine prefers growing in sandy habitats such as coastal bluffs, dunes, and slightly more inland at elevations up to 330 ft (100 m) near the Pacific Coast from British Columbia through California.
Growing Conditions: full sun, in sandy to course dry soil, drought tolerant.
Good for use in soil stabilization and in locations of drought and poor soil fertility. Lupinus arboreus has the ability to fix soil nitrogen. It is an aggressive seeder and can be invasive.