ID and Manage Atlantic White Cedar

Atlantic white-cedar (Chamaecyparis thyoides), also called southern white-cedar, white-cedar, and swamp-cedar, is found most frequently in small dense stands in fresh water swamps and bogs. Heavy cutting for many commercial uses during this century has considerably reduced even the largest stands so that the total volume of this species growing stock is not currently known.

Scientific name: Chamaecyparis thyoides
Pronunciation: chammy-cy-paris thigh-oy-deez
Common names: Atlantic White Cedar, Whitecedar Falsecypress
Family: Cupressaceae
USDA hardiness zones: 4 through 9
Origin: eastern North American conifer
Uses: used where durability, light weight and resistance to weathering are important considerations.
Availability: rapidly dwindling tree species

Height: 40 to 50 feet
Spread: 10 to 20 feet
Habit: slender column when young, spire-like crown when mature
Growth rate: 25 feet in 20 years
Needles: lateral pairs, boat-shaped with sharp-pointed tips
Growth rate: fast
Landscape value: useful on low and boggy sites within native range

Leaf color: bluish green to bright green
Leaf type: single needle
Leaf marks: resinous glands on back
Leaf shape: needle-like, ovate to triangular, flat or keeled
Leaf venation: none, or difficult to see
Leaf type and persistence: evergreen
Leaf blade length: less than .2 inches
Fall color: no fall color change
Fall characteristic: not showy

Atlantic white-cedar grows in a narrow coastal belt (50 to 130 miles) wide from southern Maine to northern Florida and west to southern Mississippi. White cedar grows on wet ground or in swamps, sometimes on sandy soils, usually on muck or peat and usually in pure stands. Favored soils include the orders of Spodosols and Histosols. Prefers full sun and will not tolerate hardwood competition.

Flowering and Fruiting - White-cedar is monoecious, but the staminate and pistillate flowers are produced on separate shoots. The flower buds are formed in the summer and, though minute, are discernible in the fall or winter. The cones mature at the end of the first growing season. Full-grown cones are spherical, about 0.2 inches in diameter and contain 5 to 15 winged seeds.

Root Habit - Atlantic white-cedar has a shallow root system. In swamps where the lower soil layers are permanently saturated with water, the roots are confined chiefly to the upper 1 to 2 feet of peat. Where the water table occurs at lower levels and the soils are more deeply aerated, the roots often penetrate to greater depths.

Damaging Agents - White-cedar suffers very little damage from insects or diseases. Wind via blow-down on typical swamp sites is a problem because of the tree's shallow root system, especially in stands that have been opened by partial cuttings. The tree also suffers from wildfire, especially crown fires that kill white-cedar

Cultivars - There are over 40 cultivars used in the landscape, according to horticulturist Mike Dirr. Most varieties do well in gardens and often used for wetland reclamation.