Big-leaf maple

Acer macrophyllum

Native range

Native to the coastal areas of north west America from Vancouver Island south to central California. It is found naturally in forest types with conifers such as Douglas fir and Sitka spruce.

Provenance choice

Very few plots have been established in Britain and no provenance trials have been carried out; seed sources from Washington should be preferred.

Site requirements

A species of intermediate shade tolerance which should be cold hardy throughout Britain but appears to be best suited to a humid climate with > 1000 mm rainfall. Not very tolerant of exposure. Prefers soil of poor to medium soil fertility and of fresh to moist soil moisture. It is not suited to very dry or very poor soils, to alkaline conditions or to peat soils.

Pests and pathogens

Susceptible to Verticillium wilt, overmature bigleaf maples are often decayed by root rot (Armillaria spp.) and butt rots (Ganoderma applanatum). In the USA it can also be affected by P. ramorum.


This species could find a greater role in western parts of Britain, particularly on acid brown earths where sycamore and Norway maple are not as suited.