Neat, symmetrical plants often mistakenly trimmed into odd geometrical formsglobes, cones, cylinders. Juvenile foliage is feathery, with small, needlelike leaves; mature foliage is scalelike, carried in flat sprays. Foliage in better-known selections is often yellow-green or bright golden yellow. Small (12- to 34-in.-long) cones are green or bluish green, turning to brownish. Although arborvitaes will take both damp and fairly dry soils, they grow best in well-drained soil. Bagworms and spider mites are common pests on all species.
T. occidentalis. AMERICAN ARBORVITAE. Zones US, MS; USDA 6-7. Native to eastern U.S. Upright, open growth to 3060 ft. tall, 1015 ft. wide, with branches that tend to turn up at ends. Bright green to yellowish green leaf sprays. Foliage turns brown in severe cold. Needs moist air to look its best. Basic species is seldom seen, but smaller garden selections are common. Among these, the taller ones make good informal or clipped screens, while lower kinds are often used around foundations, along walks or walls, as hedges. Be sure to check on the ultimate height of selections used for foundation plantings; plants are too often seen wedged under an overhang at the corner of a house. Also keep in mind that deer find them very tasty. The following are some good choices.
'Brandon'. Fast growth to 1215 ft. tall, 68 ft wide. Useful as screen.
'Degroot's Spire'. Narrow column with spirally arranged branchlets for a full look. Grows slowly to 1520 ft. tall, 45 ft. wide.
'Golden Globe'. Dense, rounded growth to 35 ft. tall and wide. Bright golden yellow foliage contrasts beautifully with deep green or blue-green evergreens. Does not sunburn even in full sun.
'Hetz Midget'. Globe-shaped plant with rich green foliage. Not likely to exceed 34 ft. tall and wide.
'Nigra'. Dense, dark green cone to 2030 ft. tall, 45 ft. wide.
'North Pole'. Narrow, upright column to 1015 ft. tall, 57 ft. wide, with dense, dark green foliage.
'Polar Gold'. Narrow cone grows 1215 ft. tall, 46 ft. wide, with dense, fine-textured golden foliage. Resists winter burn.
'Rheingold'. Cone-shaped, slow-growing, bright golden plant with a mixture of scale and needle foliage. Even very old plants seldom exceed 6 ft. tall and wide.
'Smaragd' ('Emerald', 'Emerald Green'). Neat, dense-growing, narrow cone to 1015 ft. tall, 34 ft. wide. Holds its color throughout winter.
'Techny'. Compact, broad-based pyramid to 1520 ft. tall, 1012 ft. wide. Dark green, soft-looking foliage resists winter burn.
'Woodwardii'. Widely grown, dense, globe-shaped shrub with rich green color. May attain considerable size with age but stays small over a reasonably long period; to 4 ft. high and wide in 10 years.
'Yellow Ribbon'. To 810 ft. tall, 23 ft. wide, with bright yellow foliage throughout the year.
T. platycladus orientalis (Thuja orientalis). ORIENTAL ARBORVITAE. Zones US, MS, LS, CS, TS; USDA 6-11. Native to northern China, Manchuria, Korea. Species (to 25 ft. tall, 15 ft. wide) is rarely grown; nurseries offer more attractive, shrubbier selections. Widely used around foundations, by doorways or gates, in formal rows. Less hardy to cold than T. occidentalis but tolerates heat (grows all the way to Key West). Has survived well in nematode- infested soils. Give good drainage; protect from reflected heat of light-colored walls or pavement.
'Aurea Nana'. DWARF GOLDEN ARBORVITAE, BERCKMAN'S GOLDEN ARBORVITAE. Golden-foliaged, compact globe. Usually 3 ft. tall and 2 ft. wide but can grow as high as 5 ft. Sometimes sold as T. o. 'Berckmanii'.
'Bakeri'. Compact, cone shaped, bright green. To 58 ft. high, 4 ft. wide.
'Blue Cone'. Dense, upright, conical; good blue-green color. To 8 ft. tall, 4 ft. wide.
'Bonita' ('Bonita Upright', 'Bonita Erecta'). Rounded, full, dense cone to 3 ft. tall, 2 ft. wide. Dark green with slight golden tinting at branch tips.
'Fruitlandii'. FRUITLAND ARBORVITAE. Compact, upright, cone shaped, with deep green foliage.
'Minima Glauca'. DWARF BLUE ARBORVITAE. To 34 ft. tall and wide. Blue-green foliage.
'Raffles'. Resembles 'Aurea Nana' but is smaller, with denser growth and brighter color.
'Westmount'. To 3 ft. tall, 2 ft. wide. Green foliage has yellow tips throughout the growing season.
T. plicata. WESTERN RED CEDAR. Zones US, MS; USDA 6-7. Native from coastal Northern California north to Alaska and inland to Montana. One of the West's most beautiful and imposing native trees. Can reach 200 ft. tall in the temperate rain forests of coastal Washington. Does surprisingly well in the lower Midwest and Upper and Middle South if planted in moist, fertile, well-drained soil; it can grow at least 23 ft. per year. Makes a magnificent lawn tree, but give it plenty of roomin gardens, it may reach 75 ft. tall and 25 ft. wide. Selections include the following.
'Atrovirens'. Narrow pyramid to 70 ft. tall, 25 ft. wide, with gracefully drooping limbs.
'Clemson Select'. Good tolerance of heat and cold. To 2530 ft. tall, 810 ft. wide. Bright green foliage; new growth has creamy highlights.
'Fastigiata'. Narrow, erect growth to 8090 ft. tall, 2025 ft. wide. Very dense foliage; fine for tall screen.
'Green Giant'. Hybrid between T. plicata and T. standishii, a Japanese species. Can grow 35 ft. a year, ultimately reaching 3050 ft. tall, 1020 ft. wide. Shear as a tall hedge or use as a tall screen. Good substitute for Leyland cypress.
'Hillieri'. Irregularly shaped, dense plant to 610 ft. high and wide, eventually larger.
'Spring Grove'. To 810 ft. high in five years; ultimately reaches 4060 ft. tall, 1015 ft. wide. Can be sheared as a hedge.
'Stoneham Gold'. Dense, slow-growing dwarf to 6 ft. tall, 2 ft. wide. Orange-yellow new growth.
'Zebrina'. Slow grower; same size as species. Foliage is banded in green and golden yellow. Often sold as 'Aurea', a less commonly seen selection with green foliage tinted golden.