Walnut tree trouble

[Grub]

I have friend that has a young walnut sapling in his garden but has found the outer leaves are going brown. Does anyone know what could cause this?

[David E. Ross]

I assume from your address that this is an English walnut (Juglans regia). These are often attacked by various insect pests including aphids, scale, codling moths, and spider mites. While a mature tree will likely survive such attacks, they can kill a young tree.

Also, walnuts require deep soil and do not thrive if other plants grow within their drip lines (the extent of their feeder roots).

Walnuts can be quite messy (sooty mildew and a sticky drip from insects) and not very attractive (leafless for a long time each year). If your friend nevertheless wants to keep his tree, he should consult a good local plant nursery or a professional arborist.