Ceanothus or californian lilac are evergreen shrubs which can grow into small trees if left on their own. They have small, oval dark green leaves but are grown mainly for their blue, white or pink flowers that continue all through spring and summer. Ceanothus are suitable for growing in a shrub border or against a sunny wall. Plants that are trained against a wall can grow to twice the height of those without support and only need trimming lightly after flowering. They can also be used as ground cover to minimise the need for weeding. Ceanothus should be grown in fertile, well-drained soil.