856 Calocedrus decurrensCommon Names: incense cedar, incensecedar Family: Cupressaceae (cypress Family)
Incense cedar is an evergreen tree with a skinny, columnar shape in youth, becoming only a little more rounded at maturity. In its native habitat it can get as large as 150 ft (45.7 m) tall with a trunk diameter of 6 ft (1.8 m). In these very large trees, the long straight trunk is swollen and buttressed at the base and usually free of branches for half its length. Most trees in cultivation are pencil-shaped, 30-50 ft (9.1-15.2 m) tall and 8-10 ft (2.4-3.1 m) wide. The bark is light reddish brown and scaly; in large trees it is fibrous with deep furrows. The branches are flattened, and they branch into flat vertical fanlike sprays of pleasantly aromatic foliage. The mature leaves are like flat overlapping scales, a quarter-inch long, and closely pressed against the branchlets. Juvenile leaves on new leader shoots are more elongate, to 1/2 in (1.3 cm) long. Male and female cones are small and inconspicuous, and borne on different branches of the same tree. 'Intricata' is a selection with twisted, contorted branches and a smaller final size. 'Aureavariegata' has foliage with yellow blotches. 'Compacta' grows in a dense round bush to 6 ft (1.8 m) tall and just as wide. 'Riet' is even smaller, a globose dwarf that stays under 3 ft (0.9 m) tall and wide.
Incense cedar Calocedrus decurrens is native to the Cascade Mountains of Oregon, and the Sierra Nevada of California, extending into Baja California. They usually occur on slopes from 2000 to 8000 ft (610-915 m) above sea level in the company of various fir and pine species. There are only three species of Calocedrus and the other two occur in China.
CultureIncense cedar does best on well-drained, slightly acidic sandy loams in cool, mountainous areas. Outside its natural range it tends to stay smaller and bushier. Even under ideal conditions, incense cedar is a slow growing tree. But, it can live 1000 years or more. Light: Full sun or part shade. Moisture: Incense cedar needs lots of moisture to realize its full potential as a large tree. If it gets less water than ideal it will survive, but remain as a smaller, bushy, but still attractive specimen. Hardiness: USDA Zones 6 - 8. Incense cedar does quite well in zones 7 and 8, but usually doesn't get as large as it does up north. Propagation: Incense cedar is difficult, but not impossible, to propagate from cuttings. They usually are propagated by seed which requires a period of cold stratification. Named cultivars are often grafted onto seedlings of this species or on seedlings of the closely related American arborvitae(Thuja occidentalis).
The generic name means "beautiful cedar", and that it is. The tall, columnar incense cedar is a handsome specimen for framing a formal landscape. A line of them, like soldiers at attention, adds a formal dimension to driveways and makes a great windbreak or tall screen.
Originally, wooden pencils were made from eastern red cedar (Juniperus virginiana), but when those trees were over-harvested, the industry moved west and switched to incense cedar.
The shape of the crown of incense cedar, like other members of the Cupressaceae, varies with the climate in which it is grown. Where summers are warm and moderately wet, and winters are cool or cold and relatively dry, the tree develops its most extreme columnar shape. In Mediterranean type climates, where summers are hot and dry, and winters are either cold or warm, but wet, it develops a broad, more open crown. The habit is intermediate in climates like that of the eastern U.S., with hot, humid summers and very cold winters.
See the Floridata profile for Japanese black pine (Pinus thunbergii) for a review of how the cypress family,Cupressaceae, fits in taxonomically with all the other conifers.
Steve Christman 11/13/00; updated 1/18/04