Lorenzo Blogs: Japanese Raison Tree

Thursday, March 6, 2014

Japanese Raison Tree

Hovenia dulcis

An extremely beautiful and tree with an ascending, oval crown that makes for an excellent shade tree.
Native to China and long cultivated in Japan; it reaches up to 60 feet or sometimes more. Some records include: fastest recorded growth rate - 6 feet ( 3.5 feet is more average on ideal sites ); largest on record - 115 x 61 feet with a trunk diameter of 4.3 feet; largest in U.S. - 90 x 52 feet at Morris Arboretum in Philly, PA. Another large tree near Philly grows at Taylor Arboretum at Wallingford. Moderately long-lived, the Japanese Raison Tree can persist as long as 300 years.
The attractive, heart shaped foliage is deep blue green above and light green below. The leaves are up to 11 x 6 inches in size. The leafstalks are also very long, reaching a maximum length of 11 inches. Autumn color is brilliant.
The foliage looks somewhat like that of the Balsam Poplar.
The mild scented, yellow-green flowers are not very visible but are borne in summer on sprays carried on thick stalks.
The interesting small red fruits are massed in large clusters in September and October. This tree can produce fruits in as early as 3 years with an eventual up to 10 pounds of fruits in a year.. This tree is self fertile. The Raisons" are sweet.
The bark is gray-white, smooth and birch like later becoming gray with narrow, shallow furrows.
The Japanese Raison Tree is very easy to grow on any moist, fertile, well drained soil in full sun. It does not enjoy prolonged droughts, low humidity and hot dry winds. Hardy zones 5 to 9 and tolerates as low as -22 F. This tree is not generally prone to pests or diseases.
Propagation is from half hardened cuttings taken in summer or from seed sown immediately upon ripening. Seeds germinate better if you file the hard seed coat before sowing. The seeds can also be soaked in concentrated sulfuric acid then washed off.

* photos taken on May 16 2010 @ Cylburn Arboretum, Baltimore, MD