Ceanothus papillosus, commonly known as Wartleaf Ceanothus, is an evergreen shrub native to the chaparral and mixed evergreen forests of California, particularly on coastal mountain slopes. It typically grows to a height of 3-6 feet (1-2 meters) with a similar spread. The shrub is characterized by its oblong, dark green leaves that are covered in glandular bumps, giving them a distinctive texture. From late winter to early spring, Wartleaf Ceanothus produces clusters of bright blue flowers that are highly attractive to bees and butterflies, adding to its ornamental value.

Wartleaf Ceanothus is appreciated for its drought tolerance and ability to thrive in poor, rocky soils, making it an excellent choice for water-wise gardens and naturalistic landscapes. It is often used for slope stabilization, habitat restoration, and as an attractive feature in xeriscaping. This plant prefers full sun to light shade and requires minimal water once established, reflecting its adaptation to the Mediterranean climate of its native range. While generally low-maintenance, it can be susceptible to root rot if overwatered or planted in poorly draining soils. It is also prone to fungal diseases in humid conditions. Cultivars such as ’Blue Sapphire’ and ’Frosty Blue’ offer variations in form and flower color for garden use.CC BY-SA 4.0