Incense cedar is a large, long-lived conifer native to the mountains of California, Oregon, Nevada, and northern Baja California, growing from low foothills to elevations above 9,000 feet. In gardens it typically develops a narrow columnar to broadly pyramidal form and works well as a tall screen, windbreak, or solitary specimen on large properties.
It tolerates clay, loam, or sandy soils but requires good drainage; waterlogged conditions promote root disease. Once established it is notably drought tolerant, suiting it well to western North American summers. Growth is moderate in youth and slows with age. Bark on older trees is reddish-brown, deeply furrowed, and fibrous; the flat-sprayed, scale-like foliage is strongly aromatic when crushed. A soil pH of 5.0–7.5 is acceptable. In colder portions of its range, young trees benefit from windbreak protection during their first one or two winters.
The wood is extremely decay-resistant and is the primary material used worldwide for pencil casings—most cedar pencils are made from incense cedar, not from true cedars. Indigenous peoples of California and Oregon used the split wood for construction, bows, and stakes, and wove the fibrous bark into baskets and mats.
Phytophthora Root Rot
Wilting despite moist soil, yellowing leaves, stunted growth, and dark, decayed roots and crown tissue. Vines may collapse during hot weather.
Plant in well-draining soil and avoid waterlogging. Remove and destroy affected vines. Improve drainage with raised beds or amended soil and avoid overwatering.
Armillaria Root Rot
Thinning, yellowing canopy with progressive dieback; white, fan-shaped mycelial mats visible beneath bark at or just below the soil line; honey-colored mushroom clusters appearing at the trunk base or on surface roots in autumn.
No chemical cure exists. Improve drainage and avoid any injury to roots or trunk. Remove severely infected trees along with as much root material as possible. Do not replant susceptible species in the same spot.
Seiridium Canker
Elongated, sunken cankers on branches or trunk with heavy amber to brown resin exudate. Foliage above the canker turns yellow then brown and dies. Multiple cankers can girdle a branch or stem completely.
Prune infected branches 6–8 inches below the visible canker margin and dispose of material off-site. Sterilize tools with 70% isopropyl alcohol between every cut. No curative fungicide is available; focus on reducing tree stress through proper site selection, avoiding overhead irrigation, and ensuring good soil drainage.