Tanoak Tanbark-oak

Lithocarpus densiflorus (Fagaceae), now reclassified as Notholithocarpus densiflorus, is a broadleaf evergreen tree native to southwestern Oregon and California. It can reach 130 feet in the California Coast Ranges, though 32 feet is more typical in cultivation. The habit is conical to rounded with large horizontal branches. Thick, leathery, light green leaves persist year-round. White male catkins turn rust-colored, and acorns take two years to mature.

Tanoak prefers sun to part shade on moist soil across a broad pH range (4.5 to 8.5) and performs best in a humid atmosphere. It has moderate water needs. Dwarf cultivars are available for smaller spaces. The species is highly susceptible to sudden oak death (Phytophthora ramorum) and also documented for Armillaria root rot. Tanoak acorns were a staple food for indigenous peoples of California and southwestern Oregon, processed by leaching to remove tannins. Hardy in Zones 6a to 9b.