Thanks all, I will try some cuttings and also use some
seeds from the berries. The plant that is producing the
berries is in fact a tree. It's very gnarled and must
be 15' tall. It forms part of a hedgerow between our
allotments and a farmers field.

I can't see any seedlings around, as I guess there's
too much competition for light, from hazel and cob.
Although there is no real problems for space as I own
an allotment, are there smaller, more compact
varieties?