Common Name:

General Information

Tsuga diversifolia is an evergreen tree with a conical crown; it can grow up to 25 metres tall, though is likely to be less than 15 metres in cultivation. The straight, cylindrical bole can be up to 100cm in diameter[, , ]. In the north of its range the tree is reduced to a shrub around 150 - 200cm tall[].
The tree is exploited on a commercial basis in Japan for its timber[]. It is often grown as an ornamental in Japan, though is less used elsewhere since it can be slow-growing[, ].
A fairly widespread and common species with no major threats. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

Range

E. Asia - central and southern Japan, Korea

Habitat

Cool-temperate to subalpine slopes, at elevations from 1,300 - 2,500 metres, sometimes descending to 700 metres[].

Properties

Conservation Status	Least Concern
Other Uses Rating
Habit	Evergreen Tree
Height	20.00 m
Cultivation Status	Ornamental, Wild

Cultivation Details

Tsuga diversifolia is found in central and southern Japan, where the climate is cool, with cold, snowy winters and abundant rainfall in the summer. The mean annual precipitation is in the range 1,000 - 2,500 mm[]. It can tolerate occasional temperatures falling as low as -25°c[].
Prefers a moist, well-drained soil in part shade to full shade[]. Prefers cool, moist, woodland conditions in part shade locations, but tolerates full sun in the northern parts of its growing range. It is intolerant of drought and should be watered regularly in prolonged dry spells, particularly when plants are young[]. Requires a position sheltered from strong winds[].
The tree regenerates very well in the wild as it can tolerate dense shade when young - it forms pure stands in places[].
As and ornamental tree it is planted in Japanese gardens and parks; it is also used in bonsai culture. In Europe and North America it is less commonly used, being slow growing and often remaining shrub-like for many years. A dwarf form (cultivar) which grows very slow is used for rockeries. Hemlocks are unsuitable as Christmas trees, because when cut and taken indoors they loose their leaves sooner than any other conifer[, ]

Edible Uses

None known

Medicinal

None known

Other Uses

In the past the wood was mainly used in Japan to provide pulp for making paper, but now this commodity, requiring vast resources, is mainly imported. Instead, the use of the wood has largely shifted to construction, carpentry, and joinery and, as the wood is generally dense and moderately hard and sometimes attractively figured with reddish brown heartwood and lighter sapwood, it is also used for furniture[].

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[].