Japanese red-cedar (JCR) - Forest Research

Native range

Native to the central and southern islands of Japan where it is a major timber species.

Provenance Choice

Very limited provenance testing has been carried out and seed production from British plots is unreliable; seed should be sourced from the northern part of the natural range.

Site Requirements

The species is adapted to a warm maritime climate and best growth in Britain is to be found in areas with >1200 mm annual rainfall. The need for warm growing conditions means that the best stands are to be found in Wales or south-western England where the species can be a very high volume producer. Best growth is on soils of poor to rich soil nutrient status and slightly dry to moist soil moisture. It is not suited to very poor or dry soils, to peats or to alkaline soils. This is a high quality timber species, although pruning is an important component of management regimes in Japan. A very shade tolerant species which is moderately resistant to exposure although the crowns can be liable to snow break.

Pests and Pathogens

Japanese cedar is susceptible to Phytophthora root disease, including P. cinnamomi. It is also considered to be susceptible to Armillaria root rot (honey fungus). Elsewhere, it has been reported to be affected by Juniper blight (Phomopsis juniperovora) which is present in Britain and already widespread on juniper.

Use

Climate warming should increase the range of sites where the species will grow well such as in western Scotland.

Japanese red-cedar is categorised as a Plot-stage species. These are species that have not been planted on any significant scale but have demonstrated silvicultural characteristics in trial plots and have qualities suitable for forestry objectives to justify further testing and development.