Ceanothus arboreus, commonly called feltleaf ceanothus or island ceanothus, is native to California’s Channel Islands, specifically Santa Cruz, Santa Rosa, and San Miguel. It is one of the few Ceanothus species adapted to insular environments, where it grows as a large evergreen shrub, sometimes reaching up to 20 feet in height. The flowers form dense clusters of small star-like blossoms, varying from light to deep blue. Each bloom measures only a few millimeters across but appears in great abundance during the flowering season, usually late winter through spring. The plant is notable for its felt-like leaves, which are thick, evergreen, and slightly fuzzy on the undersides, an adaptation to conserve water in the dry island climate. The plant is also drought-tolerant and can survive in nutrient-poor soils, contributing to its use in California native gardens. Cultivars such as ‘Cliff Schmidt’ and ‘Trewithen Blue’ are valued for their reliable blooming and striking floral displays.