The tree lupin is an evergreen, perennial shrub or small tree to a height of about 2 m. It is native to California. This attractive plant is nitrogen fixing and a good nurse crop. It is tolerant of frost and does better with some summer watering. It prefers a deep loose soil. In the UK it has become a volunteer of limestone quarries.
It is a good bee forage, flowering from late winter to early summer. A second flowering occurs in the autumn. No data is available on its value as a stock feed but it is likely that it is too toxic. Hungry kangaroos will not eat it which is an advantage in many situations. It can be cut hard to supply mulch rich in nitrogen.
It can be grown from cuttings but growing from seed is easy.