Platycladus orientalis, commonly known as Chinese Arborvitae or Oriental Thuja, is an evergreen conifer belonging to the cypress family, Cupressaceae. This species is native to northeastern parts of East Asia, including China, Korea, and parts of the Russian Far East. It is widely recognized and cultivated globally, valued for its distinctive appearance and notable hardiness. As a popular evergreen, it has found widespread use and appreciation in various landscapes and cultural practices.
Identifying Characteristics
The foliage consists of scale-like leaves that are pressed closely to the stems, forming flattened, vertical sprays. These leaves typically display a bright green color on top, often with two white bands of stomata on the underside, and may develop a bronze hue in winter. The plant’s cones present a unique characteristic, starting as small, fleshy, and bluish-green structures, often with horn-like projections on their scales. As they mature, these ovoid cones, measuring 1.5 to 2.5 cm long, ripen to a woody brown color.
The bark is thin and reddish-brown, often separating into papery scales as the tree ages. Young plants typically exhibit a dense, conical or columnar shape, which can broaden with age, reaching heights of 10 to 15 meters (approximately 33 to 49 feet) in cultivation. Some specimens can grow up to 25 feet tall and 15 feet wide. The branchlets are held vertically and nearly parallel, contributing to its distinct appearance.
Native Habitat and Growing Conditions
For cultivation, Platycladus orientalis generally thrives in USDA hardiness zones 6 through 9, though some sources extend this to 10A. While it can tolerate a range of temperatures, it may not be reliably winter hardy in the northern parts of USDA Zone 5. The plant prefers full sun exposure, although it can tolerate some light afternoon shade. It grows best in fertile, well-drained soils with medium moisture, demonstrating good drought tolerance once established.
However, it does not withstand waterlogging or consistently wet sites. Good air circulation is beneficial, and it should be sited in locations sheltered from strong winds due to its somewhat shallow root system.
Landscaping Uses and Common Cultivars
Platycladus orientalis is a versatile evergreen widely employed in various landscaping designs due to its dense foliage and adaptable growth habit. It is frequently utilized for creating hedges, privacy screens, and windbreaks, providing year-round opacity. The plant also serves as an appealing specimen tree, particularly in formal or structured garden settings, and can be pruned to form a distinctive vase shape.
Numerous cultivars have been developed to suit specific landscaping needs. For instance, ‘Aurea Nana’ is a popular dwarf variety known for its compact, globular shape and bright yellow-green foliage, making it suitable for foundation plantings or rock gardens. ‘Morgan’ is another dwarf shrub with yellowish foliage that transitions to an orange hue in winter. ‘Franky Boy’ offers a unique texture with its rounded, teardrop shape and fine, thread-like branches.
Traditional and Medicinal Significance
Beyond its horticultural appeal, Platycladus orientalis holds a long history of use in traditional Chinese medicine (TCM). Both the leaves and seeds have been utilized for various purposes. Traditionally, the leaves are employed for their hemostatic properties, helping to stop bleeding, and also to promote hair growth.
Components of Platycladus orientalis have also been associated with anti-inflammatory and antimicrobial properties. They are traditionally used to address respiratory conditions like coughs and bronchitis, and to support cardiovascular health by improving blood circulation. Culturally, this species symbolizes longevity and vitality in China, often found planted near temples and cemeteries, underscoring its enduring significance.