Japanese red pine

Synonyms: red pine, densely-flowered pine, densely-flowered pine, Japanese pine, Japanese red pine, Japanese umbrella pine, tanyosho pine, chi song, pin rouge du Japon, japanische Rotkiefer, pino rosso del Giappone, aka-matsu, me-matsu, sonamu, japansk tall, Pinus densiflora Siebold & Zuccarini.

Japanese red pine is a species of the genus Pinus in the family Pinaceae. In the wild it occurs in China in the provinces Shandong, Liaoning, Jiangsu, Heilongjiang, Jilin, in Japan (Shikoku, Honshu and Kyushu), Korea and in Russia (southern Primorsky Krai).

It grows on rocky cliffs, slopes and rocks (0-500 m above sea level) and on sandy soils and seashores (0-600 m above sea level). Occasionally it reaches 2300 m above sea level. It occurs in groups, groves, sometimes solitary. It is easily flammable but has a high regenerative capacity. It was first described in Europe by Siebold and Zuccarini in 1842. It was listed in the Red Book of the USSR and the RSFSR.

The trees reach up to 30 m in height. The trunk attains 1.5 m in diameter. Growth is moderately fast, reaching 3 m in height at 10 years. Bark orange-red, red-brown or brown-yellow, peeling, scaly.

The trees are easily flammable but regenerate well naturally. Crown umbrella-shaped, wide, very dense, spreading.

Needles are borne on short shoots in pairs, 5-15 cm long and 1 mm in diameter, acutely pointed at the tip, straight, rough-edged, stiff, dark green, giving the tree a fluffy appearance. The color does not change for winter. Buds are weakly resinous.

Cones erect or pendulous, ovoid or ovoid-conical, 3-5.5×2.5-4.5 cm, dark yellow-brown or brownish-yellow, opening at maturity. Seed scales thin, appressed, broadly rhombic, flat or turned up at the apex, rarely pyramidal and slightly ribbed.

Seeds ovoid or elliptic, 3-7 mm long and 3 mm wide; wing 1-2 cm × 5-7 mm. Pollination occurs in April-June. Seeds mature in the second year, in September-October.

Forms: 'Umbraculifera', Pinus densiflora var. Densiflora, Pinus densiflora var. Ussuriensis Liou & Q. L. Wang, Pinus densiflora var. Zhangwuensis S. J. Zhang et al.

Hardiness zone: 5 (Hardiness limit between -28.8°C and -23.3°C)

Site: sun-loving. Demanding of soil and air moisture. Grows well on well-drained loams or sandy loams. Tolerance to urban conditions is moderate.

Planting: plants should be transplanted up to 5 years old. Distance between seedlings at least 4-6 m, depth 0.8-1 m. The root collar should be placed at ground level. If the soil is sandy, it is recommended to mix the top layer with peat and clay in a ratio of 2:1:2. During planting it is recommended to add nitroammophoska or humus-rich soil and during the first 2 years after planting to apply 30-40 g/m² of mineral fertilizer.

Propagation: propagated by seeds or by layering.

Uses: The wood is used in construction and furniture making. It was the most popular building material in Japan during the Muromachi and Edo periods. Widely used as an ornamental tree in Japan, Europe and North America. In landscape design it is used as a specimen and in group plantings, as well as in heathlands and Japanese gardens. Widely used in bonsai. It is one of the most ornamental two-needle pines.