Julia Phelps mountain lilac (Ceanothus 'Julia Phelps') is a Ceanothus cultivar known for its attractive indigo blue flowers and crinkly dark green foliage. It is a hybrid of wartleaf Ceanothus (Ceanothus papillosus) and Santa Barbara Ceanothus (Ceanothus impressus). It is similar in appearance to another popular hybrid called 'Dark Star.'

This evergreen shrub has a dense, mounded growth habit and can grow up to 8 ft tall and 12 ft wide. In spring, the deep blue flowers bloom in small clusters that complement the small dark leaves. An important wildlife plant, it attracts pollinators and provides seeds and shelter for birds.

Julia Phelps mountain lilac is a good plant for the waterwise garden. It has low moisture requirements, needing little to no supplemental irrigation. In fact, too much water can damage this drought adapted shrub. Plant in fast draining sandy soil. It tolerates full sun at the coast but does better in partial shade inland. Prune after flowering, and again in fall if desired. Avoid winter pruning to maximize flower formation.