©BSNHS 2014

Walnuts produce juglone, a chemical which suppresses competing vegetation and so reduces  competition.

Walnut leaves are commonly galled by gall mites, Aceria erinea and Aceria tristriata both causing blistering on the leaves.

One characteristic that separates Walnuts from all other trees, excluding Wingnuts, is that it has a chambered pith within the twigs.

As gardeners are aware common Walnut is susceptible to honey fungus ( Armillaria spp) where as one member of the Walnut family Juglans hindsii is totally immune.

A naturalized tree introduced around 1400s but may have arrived with the Romans where it is a native of South East Europe.

A deciduous spreading tree, under ideal conditions can reach 20 -30m in height, found in orchards and gardens. Can be long lived, trees known to live up to 1000 years.

Bark very pale grey smooth when young becoming deeply fissured as maturity occurs.

Leaves are alternate, pinnate with usually seven leaflets with the terminal one the largest.

A monoecious tree, male flowers yellow-green with three stamens while female flowers in short erect clusters with two styles. Fruit rounded smooth green skin enclosing the familiar walnut seed, often eaten by squirrels long before ripe.

Semi-mature bark

June Tree of the Month - Walnut

Walnut flower

Walnut tree