Cryptomeria japonica: Japanese Cedar

Introduction

The tree keeps a billowy pyramidal form on one central trunk until close to maturity when the crown opens up into an irregular, narrow oval. It will reach a height of about 50 feet and spread about 20 feet. Old specimens can develop trunks to 3 feet in diameter. The reddish-brown bark is ornamental, peeling off in long strips, and is the most pronounced characteristic on old trees. The foliage will become bronzed during the winter but greens up again in spring. Branches usually persist on the tree with old specimens branched to the ground.

General Information

Scientific name: Cryptomeria japonica

Pronunciation: krip-toe-MEER-ee-uh juh-PAWN-ih-kuh

Common name(s): Japanese cedar

Family: Taxodiaceae

USDA hardiness zones: 6A through 8B (Fig. 2)

Origin: not native to North America

Invasive potential: little invasive potential

Uses: screen; street without sidewalk; specimen; parking lot island 100–200 sq ft; parking lot island > 200 sq ft; tree lawn 4–6 feet wide; tree lawn > 6 ft wide; urban tolerant; highway median; Bonsai; parking lot island < 100 sq ft

Availability: not native to North America

Description

Height: 40 to 60 feet

Spread: 15 to 20 feet

Crown uniformity: symmetrical

Crown shape: pyramidal, oval

Crown density: dense

Growth rate: slow

Texture: fine

Foliage

Leaf arrangement: spiral (Fig. 3)

Leaf type: simple

Leaf margin: entire

Leaf shape: awl-like

Leaf venation: none, or difficult to see

Leaf type and persistence: evergreen

Leaf blade length: less than 2 inches

Leaf color: green

Fall color: copper

Fall characteristic: not showy

Flower

Flower color: unknown

Flower characteristics: not showy

Fruit

Fruit shape: round

Fruit length: .5 to 1 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 droop; very showy; typically one trunk; thorns

Pruning requirement: little required

Breakage: resistant

Current year twig color: green

Current year twig thickness: medium

Wood specific gravity: unknown

Culture

Light requirement: full sun

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

Drought tolerance: high

Aerosol salt tolerance: unknown

Other

Roots: not a problem

Winter interest: no

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: sensitive to pests/diseases

Use and Management

Provide an acid soil and protection from winter winds. Locate the tree so air circulation is good, particularly during summer to help prevent leaf blight. Best with afternoon shade in southern part of its range. A number of cultivars are available varying in growth habit and ability to hold green foliage color in the winter. Cryptomeria is tolerant of compacted soil and performs well in parking lots and other tough, urban sites with some irrigation in drought. It makes a wonderful accent, screen, or border tree for larger properties. It may grow too large for most residential landscapes. They can be planted as street trees 10 feet back from the street in residential areas to provide an elegant flavor to the neighborhood.

Propagation is by cuttings which root slowly or by seed which germinates slowly.

'Yoshino' holds green foliage color in the winter. 'Elegans' grows to 15 feet tall.

Pests

Mites can infest the foliage.

Diseases

Leaf blight and leaf spot are two problems. Leaf blight often causes much of the interior foliage to brown, creating an unsightly specimen. Fungicide sprays help prevent the disease, as does placing the tree so it receives early morning sun to dry the foliage. Keep the foliage as dry as possible.