I have a Berberis growing very close to a larch-lap six ft. high fence.
This
fence needs regular wood treatment so the Berberis needs cutting back to
allow access for painting. The thorns are vicious hence the need to prune.
After each very heavy pruning the bush recovers fantastically !

Thank you all very much for your interest and advice. I have attacked my
Berberis - and it return it attacked me :-) - I will have a go at some
cuttings. I was surprised at the huge number of suckers.

Thanks again

kate