I have just been given a young walnut tree that has been dug up, around 3"
high, with bare roots that are now sitting in a bucket with some soil and
water. It's very healthy and has lots of leaves. I supose it's a couple of
years old at the most. I think it's the large-nut californian variety,
rather than the European type.

I suppose the best thing to do is to give it a planting prune to cut water
loss while the roots recover? I realise it's probably not the best time to
plant, but it's either give it a try or let the poor thing die().

Has anyone got any tips for me as I know nothing about them? What sort of
soil do they prefer? sun/temperature/wind preferences? There are a few
growing well in the neighbourhood so I assume that climate and soil are
roughly suitable.

Does anyone know how old they have to be before they start producing nuts?

Tim.