Calocedrus decurrens aka California Incense Cedar

Calocedrus decurrens, or incense cedar, is an evergreen conifer. It belongs to the cypress family, Cupressaceae. Despite its common name, it is not a true cedar. Its native range runs from western Oregon to northern Baja California. It also grows in California and southwestern Nevada. Wild trees grow on wooded slopes and in mountain canyons. They often share these sites with other conifers.

Garden trees often reach 30–50 feet (9.1–15.2 metres) tall. Some garden accounts give heights of 70 feet (21.3 metres). Reported spreads range from 10–26 feet (3–8 metres). Wild trees may reach 100–150 feet (30.5–45.7 metres). Some live for more than a thousand years. Young trees have a narrow, upright shape. Older trees may widen into a cone with a rounded top. Brown to gray-brown bark flakes away and adds winter interest.

Flat branchlets carry dense sprays of small, overlapping, scale-like leaves. The glossy, dark green leaves keep their color through winter. Crushed leaves give off a strong scent. This tree makes cones rather than true flowers. Both male and female cones grow on the same tree. The small male cones are yellow. Female cones have six pairs of pointed scales. They ripen from late summer into fall, depending on elevation. Ripe cones turn reddish brown and hold up to four seeds. Some remain on the tree until spring.

Grow incense cedar in full sun or part shade. It favors deep, fertile loam with good drainage and steady moisture. It also grows in other well-drained soils across varied pH levels. Mature trees withstand drought, but dry soil can kill seedlings. Shelter from drying winter winds helps in cultivation. The tree tolerates summer heat and humidity. Sources place it in USDA zones 5–8 and UK rating H7. It needs little upkeep and no routine pruning, though it tolerates shearing. Its strong root system makes transplanting difficult.

Use it as a specimen, hedge, screen, or windbreak. Its foliage feeds the young of butterflies and moths. The soft wood serves for pencils, fencing, and building work. Bark and roots have supplied material for baskets. Sources record leaf use to flavor acorns during processing. They also note past medicinal use, but report no known hazards. Aphids, cutworms, rust, heart rot, and honey fungus may occur. The tree has high flammability, despite thick bark on mature trunks.