Calocedrus spp.

incense cedar

Cupressaceae Western North America and East Asia

Deer Resistant Drought Tolerant Fragrant (moderate)

Native to North America

SunFull Sun – Part Shade

WaterLow · drought-tolerant

HardinessZones 5–8

Overview

Calocedrus spp. is a small genus of evergreen conifers in the cypress family (Cupressaceae), with species in western North America and East Asia. The California incense cedar, C. decurrens, is the largest species, forming a dense columnar to conical tree 40-150 feet (12-45 m) tall with a single trunk to 4 feet (1.2 m) across and cinnamon-brown, furrowed bark. The foliage consists of flattened sprays of scale-like leaves arranged in repeating sets of four, rich green and strongly aromatic when bruised. Plants are wind-pollinated, and the slender seed cones, about 0.8-1 inch (20-25 mm) long, hang from the branch tips and open into a shape often likened to a duck bill as they release winged seed. Calocedrus spp. grows on mountain slopes and dry ridges and tolerates heat, drought, and poor soils once established, though it grows slowly and is sensitive to waterlogging. The aromatic wood of C. decurrens is the main timber used for pencils.

Native Range

Calocedrus spp. is native to western North America and to East Asia. C. decurrens grows in the mountains of Oregon, California, and western Nevada into northern Baja California, while other species occur in China, Taiwan, and mainland Southeast Asia. Plants grow on well-drained mountain slopes in mixed conifer forest.

Suggested Uses

Calocedrus decurrens is used as a specimen, tall screen, and avenue tree in gardens with room for its narrow, columnar crown. It suits dry, sunny sites in USDA zones 5-8 and is grown as a timber tree for pencil and joinery wood. Its eventual height and slow early growth limit its use in small gardens.

How to Identify

Look for a columnar evergreen conifer with flattened sprays of scale leaves that are strongly aromatic when crushed and arranged in repeating sets of four. The bark is cinnamon-brown and deeply furrowed on older trunks. Slender cones about 0.8-1 inch (20-25 mm) long hang at the branch tips and open with a few reflexed scales. The four-part flattened sprays and pencil-wood scent separate it from arborvitae and false cypress.

Appearance

Size & Dimensions

Height40' - 150'

Width/Spread8' - 15'

Colors

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Conifers do not flower. Pollen is shed from small terminal cones in late winter and early spring, and the slender seed cones ripen within a single season. Cones open in autumn to release the winged seed, then often fall soon after.

Detailed Descriptions

Foliage Description

Rich green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

20-30 years to mature size

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun to light shade on deep, free-draining soil and tolerate heat, drought, and poor or rocky ground once their roots are established. They are hardy to about USDA zone 5 and dislike heavy, wet soils, which lead to root rot. Young trees grow slowly and need occasional summer water until settled. The dense, columnar habit develops without staking or shaping in open positions. Cedar bark beetles and heart rot mainly affect old or stressed trees.

Pruning

Pruning is generally unnecessary beyond removing dead or damaged wood, as the natural columnar form needs no shaping. A single leader keeps the top from forking into weak, competing stems. Lower limbs can be removed to raise the canopy where clearance is wanted.