Plant · P-534

English Walnut

Juglans regia

English walnut is a large deciduous tree grown for its rich, high-fat nut, which cracks free of a hard shell after the green husk splits in autumn; grafted trees start bearing at five or six years and can reach around 2.5 tonnes of nuts per hectare by seven or eight. Its roots and fallen leaves leach juglone, a compound toxic to apples, tomatoes and several other common garden plants, so what grows beneath and around it has to be chosen carefully. The wood is one of the classic furniture and veneer timbers, prized enough that a mature tree can be worth as much for its lumber as for its nuts.