Japanese larch (JL) - Forest Research

Native range

Native to a limited mountainous zone in the central island (Honshu) of Japan, although also widely planted in the northern island of Hokkaido.

Provenance Choice

Collections from British seed stands should be preferred or if these are not available provenances from the central part of the natural range should be used.

Site Requirements

A light demanding pioneer species which needs more than 1000 mm of rainfall for good growth. Cold hardy and withstands moderate exposure, although stem form can be poor especially on exposed or more fertile sites. Vulnerable to spring and autumn frosts. Best suited to mineral soils of poor nutrient status (i.e. less fertile than for European larch), and will also grow on very poor soils and on better drained peats. Very fast early height growth means that it is better suited for mixture with conifers.

Pests and Pathogens

Only rarely susceptible to the fungal disease, larch canker (Lachnellula willkommii), which causes perennial cankers that girdle or distort branches and stems. Can also be affected by Heterobasidion (Fomes root and butt rot) as well as another butt rot fungus, Phaeolus schweinitzii. More recently, Japanese larch has been found to be seriously affected by the introduced pathogen, Phytophthora ramorum, which may affect future use.

All three larches (EL, JL and HL) can be killed following attacks by the larch bark beetle, Ips cembrae, but this pest is only thought to occur in northern Britain. Trees under stress are preferentially attacked.

Use

A species whose role could have increased in western Britain with climate change, especially if planted on mineral soils to diversify spruce forests. However, susceptibility to Phytophthora ramorum has restricted its future use.

Japanese larch is categorised as a Principal tree species – widely used for forestry and will continue to be a key species unless affected by a new pest or disease or adversely affected by climate change.