Hybrid larch (HL)

Larix × marschlinsii (Syn. L. × eurolepis)

A cross between European and Japanese larches which was first observed at Dunkeld and which shows hybrid vigour.

Provenance choice

Only material from seed orchards or from controlled crosses should be used.

Site requirements

A very fast growing pioneer species with good stem form probably best suited to areas within between 700 and 1500 mm rainfall. Cold hardy and withstands moderate exposure, while susceptible to spring frosts. Best suited to mineral soils of poor nutrient status, but has also grown well on well drained peats. Will outyield both Japanese and European larch on similar sites. Vigorous height growth may make it difficult to manage in mixture.

Pests and pathogens

Occasionally susceptible to the fungal disease, larch canker (Lachnellula willkommii), which causes perennial cankers that girdle or distort branches and stems. Can also suffer striking defoliation by the needle cast fungus Meria laricis.

More recently, larch has been found to susceptible to the introduced pathogen, Phytophthora ramorum, which is causing widespread mortality to Japanese larch in western parts of Britain. Susceptibility of hybrid larch to P. ramorum is uncertain at present. It can also be affected by Heterobasidion (Fomes root and butt rot) as well as another butt rot fungus, Phaeolus schweinitzii.

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 which could be used to replace Sitka spruce on sites vulnerable to drought in eastern Scotland, but only if guaranteed hybrid material is available.