Common Name:

General Information

Tsuga sieboldii is an evergreen tree with a broadly conical crown, becoming irregular and often flat-topped with age; it can grow up to 30 metres tall. The straight, cylindrical bole is usually up to 100cm in diameter, occasionally to 250cm[, , ].
The tree is harvested from the wild for its wood which is used locally and commercially. It is often grown as an ornamental, especially in its native country.
This species has been exploited for its timber in the past 100 years, but the population reduction is not likely to exceed 30% over three generations (100 years), it is more likely to be in the range of 20-29%, hence this species is listed as Near Threatened. The reduction is based on direct exploitation, and there is also a growing impact from browsing by deer in central Japan as many seedlings are eaten, so the tree almost qualifies as Vulnerable..The plant is classified as 'Near Threatened' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - central and southern Japan, Korea

Habitat

Mixed conifer forest on hills and mountains; at elevations from 400 - 1,500 metres[, ].

Properties

Conservation Status	Near Threatened
Other Uses Rating
Habit	Evergreen Tree
Height	20.00 m
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Tsuga sieboldii grows on various soils derived from granitic or volcanic rock. The climate is moist temperate, with annual precipitation between 1,000 mm and 2,000 mm, the winters are relatively mild[]. The plant can tolerate occasional temperatures falling as low as -20°c[].
A plant of cool, shady mountainsides, where it is usually found on mildly to strongly acid soils, in lowland areas it requires a cool, sheltered microclimate, such as a damp, clay hollow that is moderately well drained[].
Young trees are very shade tolerant and do not like full sun, though they become more tolerant of sunny positions as they grow.
The tree takes around 30 years from seed before it starts producing seed[].
As an ornamental tree it is grown in Japanese gardens and parks, temple grounds and also in large pots. This species was introduced to Europe (the Netherlands) in 1850 and is still in cultivation on both sides of the North Atlantic, but uncommon. It is slow growing and often makes a shrubby, spreading tree with a dense crown[].

Edible Uses

None known

Medicinal

None known

Other Uses

The uses of the wood of Southern Japanese Hemlock are mainly construction, carpentry and furniture making. It grows less abundantly than Northern Japanese Hemlock and was therefore not used on such a large scale as a source for paper pulpwood[].

Propagation

Seed - it germinates better if given a short cold stratification[, ] and so is best sown in a cold frame in autumn to late winter. It can also be sown in early spring, though it might not germinate until after the next winter. If there is sufficient seed, an outdoor sowing can be made in spring[]. Pot-grown seedlings are best potted up into individual pots once they are large enough to handle - grow them on in a cold frame and plant them out in early summer of the following year. Trees transplant well when they are up to 80cm tall, but they are best put in their final positions when they are about 30 - 45 cm or less tall, this is usually when they are about 5 - 8 years old[]. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance[].