Introduction

This rapidly-growing North American native evergreen reaches 30 to 40 feet in height with a 15- to 25-foot-spread. It is referred to as Cupressus glabra or Cupressus arizonica var. arizonica by some botanists. The green foliage has a silver/gray shimmer and the branches are more open than most other species of juniper. The inconspicuous flowers are followed by small, 1-inch cones which persist on the tree. The peeling brown bark becomes gray with age. Arizona cypress is often used as a specimen or windbreak planting and is a common sight in west Texas and the southern High Plains where it tolerates the hot, dry conditions with ease.

General Information

Scientific name: Hesperocyparis arizonica var. arizonica

Pronunciation: hes-per-oh-SY-pair-iss air-ih-ZAWN-ih-kuh variety air-ih-ZAWN-ih-kuh

Common name(s): Arizona cypress

Family: Cupressaceae

USDA hardiness zones: 7A through 11 (Figure 2)

Origin: native to North America

Invasive potential: not assessed/incomplete assessment

Uses: specimen; screen

Description

Height: 30 to 40 feet

Spread: 15 to 25 feet

Crown uniformity: symmetrical

Crown shape: columnar, pyramidal

Crown density: dense

Growth rate: moderate

Texture: fine

Foliage

Leaf arrangement: opposite/subopposite (Figure 3)

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: green, blue or blue-green

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: yellow

Flower characteristics: not showy

Fruit

Fruit shape: round

Fruit length: 0.5 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 don't droop; showy; typically one trunk; thorns

Pruning requirement: little required

Breakage: susceptible to breakage

Current year twig color: green

Current year twig thickness: thin

Wood specific gravity: unknown

Culture

Light requirement: full sun

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

Drought tolerance: high

Aerosol salt tolerance: unknown

Other

Roots: not a problem

Winter interest: no

Outstanding tree: no

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: sensitive to pests/diseases

Use and Management

It can be found growing with a single trunk or in clumps. It is probably best used in landscapes which are not irrigated since it is susceptible to juniper blight. Many locations in the eastern part of the country are too humid to successfully grow this tree. It is most often found in the west and in the drier parts of Texas and Oklahoma.

Roughbark Arizona cypress should be grown in full sun on well-drained soil. Although it will tolerate clay soil, the shallow roots will not gain as secure an anchor as they might in other soils and the tree may, as a result, topple over during wind and rainstorms.

Cultivars include: 'Compacta'—low, conical; 'Gareei'—silver-blue foliage; 'Glauca'—leaves silvery-grey; 'Greenwood'—medium silver/grey/green; 'Oblonga'—horizontal branches, producing oblong effect, leaves grey/green; 'Verhalenii'—leaves bright glaucous-blue, softer and more graceful than wild forms; 'Watersii'—narrowly pyramidal, compact.

Propagation is by seed or grafting.

Pests

Bagworms.

Diseases

Juniper blight, especially in cool, humid regions.

A stem canker has devastated large numbers of trees in various parts of the country.