Ceanothus papillosus Roweanus

Ceanothus papillosus “Roweanus” – Californian Lilac

Abundant dense heads of bright blue flower clusters in spring, contrast with the dark foliage.


This is a large shrub or small tree, typically growing to 4-3M tall and wide. It presents as a dense block of dark green foliage when not in flower. When in flower it is almost completely covered in bright blue flowers, which very unusual – Wisteria is a climber, Hydrangeas are smaller, Lilac are not this bright blue, and Plumbago is smaller and also not this bright blue.


C. papillosus is endemic to California, where it grows in open habitat on the slopes of the coastal mountain ranges. It is in the Buckthorn family (Rhamnaceae) – It is not a Lilac. It is loved by bees, absolutely humming on a sunny morning when in flower.

Soil / Aspect:

C. papillosus thrives in full sun and low rainfall and requires good drainage. It is tolerant of coastal exposure, and tolerates frosts down to -10°C. This is a nitrogen fixing shrub which survives on poor soils. It is a tough plant.


Whilst this plant can be left to its own devices, it can be a bit much for most gardens. We give it a hard prune after flowering each year. It is often limbed-up (the lower branches removed to reveal bare stems) to allow it to be underplanted, as with Plectranthus cilliatus in our garden.