I have had a blackberry briar growing out of a one foot square hole the corner my patio for nearly 30 years - I believe it is Bedfordshire Giant. It has cropped well and reliably. When I first planted it, it would put up two new stems each spring - in November I would cut the previous years stems that had fruited right down to the ground, and tie in the new ones as replacements. This worked fine for many years - but in recent years it has started only putting up one new shoot. This year, although the one stem from last year fruited well and seems healthy, it has put up no replacement shoot at all. I've just cut this years stem back to a few side branches that still have leaves in the hope that it will put up a new shoot next spring - but I'm wondering if, after 28 years of service it has simply given up. Is there anything else I can do to maximise its chances of recovery?