Introduction

Often seen at 40 to 60 feet tall by 15 feet wide in its cultivated form, this North American native can soar to heights of 100 to 150 feet in the wild. The massive, thick trunk and formal, upright, conical silhouette is softened by the gently weeping tips of the short, upright branches. The flattened, dark blue-green branchlets have a delicate, almost fern-like appearance, and are nicely complemented by the rough, deeply furrowed, reddish-brown bark. Available in a wide variety of forms and bluish foliage colors, Lawson falsecypress still remains today an important timber trees from the Pacific Northwest. But it is rare in the nursery trade and probably not well adapted to most landscapes.

General Information

Scientific name: Chamaecyparis lawsoniana

Pronunciation: kam-eh-SIP-uh-riss law-so-nee-AY-nuh

Common name(s): Lawson falsecypress, Port Orford cedar

Family: Cupressaceae

USDA hardiness zones: 5B through 7B (Fig. 2)

Origin: native to North America

Invasive potential: little invasive potential

Uses: specimen; screen; bonsai

Availability: not native to North America

Description

Height: 40 to 60 feet

Spread: 15 to 25 feet

Crown uniformity: symmetrical

Crown shape: upright/erect, columnar, pyramidal

Crown density: dense

Growth rate: moderate

Texture: fine

Foliage

Leaf arrangement: opposite/subopposite

Leaf type: simple

Leaf margin: entire

Leaf shape: scale-like

Leaf venation: none, or difficult to see

Leaf type and persistence: evergreen

Leaf blade length: less than 2 inches

Leaf color: blue or blue-green, green

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: red, blue

Flower characteristics: not showy

Fruit

Fruit shape: round, cone

Fruit length: less than .5 inch

Fruit covering: dry or hard

Fruit color: brown

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically one trunk; thorns

Pruning requirement: little required

Breakage: resistant

Current year twig color: green, brown

Current year twig thickness: thin

Wood specific gravity: 0.43

Culture

Light requirement: full sun

Soil tolerances: clay; sand; loam; acidic; slightly alkaline; well-drained

Drought tolerance: moderate

Aerosol salt tolerance: moderate

Other

Roots: not a problem

Winter interest: no

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

Lawson falsecypress is only suited for the largest landscapes such as in parks, golf courses, and large industrial or commercial landscapes or estates. The unusually blue foliage and dense, symmetrical growth habit make it ideally suited as a screen in a sunny spot protected from constant wind. It has somewhat picky cultural requirements and should be grown in full sun in moist, well-drained soil (not clay), in areas of moderate to high humidity, and preferably where the trees can be protected from harsh winds. These sites may be hard to find in the East.

Various cultivars are available with different foliage colors (golden, blue, or silver-variegated) and different growth forms (dwarf, columnar, and low-spreading).

Propagation is done easily by cuttings taken in fall, or by seeds, with difficulty.

Pests

No pests are of major concern.

Diseases

A fungus damages this species by causing root rot, which eventually kills the tree. Plant only in the most well-drained soil.

There is also a branch canker which can cause branch dieback.