Platycladus orientalis (Oriental Arborvitae, Oriental Cedar)


Michael's Opinion

An elegant plant used as a hedge, or as a solitary specimen in the landscape.

Botanical Information

FamilyCupressaceae
GenusPlatycladus
Speciesorientalis
SynonymsThuja orientalis
CategoryWoody
TypeTree (evergreen)
OriginChina, introduced before 1737.
Pronunciation

Details

USDA Hardiness Zone 6-11
USDA Hardiness Ref.
Canadian Hardiness Zone6
Canada Hardiness Ref.
RHS Hardiness ZoneH7
RHS Hardiness Ref.
Temperature (°C)-23 to -26
Temperature (°F)0 to -10
Height5 - 8 m
Spread3 - 5 m
GrowthSlow
Flowering PeriodMay

Description and Growing Information

General DescriptionTransplants well, tolerant of most conditions, except for boggy sites. Best in full sun, tolerates some shade. Not to be planted where it will be exposed to winter wind; it is pH adaptable.
ID CharacteristicBruised leaves emit an odour, branchlets arranged in a vertical pattern. Hard horn-like cones. It tends to keep its green colour in winter. Shredding gray-brown bark. There is a distinct groove on the back of scales.
ShapeDense, conical shape.
LandscapeSuited to hedging, where it produces a dense form when clipped. It can be used also as an evergreen accent either clipped or left slightly informal.It unlike, its cousin Thuja occidentalis will regenerate from old wood permitting the renovation of old hedges.
PropagationSeed germination is relatively easy. Stratification of seeds for 60 days at about 4°C may be helpful. It may also be propagated by cuttings.
CultivationEasily transplanted, produces seed freely in cultivation, prefers a moist loamy soil, and grows best on freely draining sites.
PestsBagworm, spider mites and canker.
HabitatSteep dry rocky valley slopes, moist, well drained soils, Korea and China.
Bark/Stem DescriptionShredding and brown to grey-brown in colour.
Leaf DescriptionSmaller than those of other species, distinctly grooved on the back, those on main axis about 1.25 cm long, triangular, ending in a blunt point.
Flower DescriptionMonoecious, terminal, solitary.
Fruit DescriptionCones roundish egg-shaped, 2 cm long, fleshy, bluish before ripening, scales usually 6 ovate, medium brown colour.
Colour DescriptionBright yellow-green to grass-green in youth, darker green when older.
Texture DescriptionMedium-fine.

Photographs