They are multi-stemmed, large shrubs. It is difficult to be sure of size, but they look substantially bigger than anything that I have seen growing, even older plants where there is not a chance that they'd have been pruned. Must be the local air
Black Knight is a slow-grower in all senses - slow to make elongation growth and slow to proliferate/divide/branch.
Ask the owner of the first for one stem, from ground-level. Strike that, trim back and graft Black Knight on the top.
My 25-year-old plants here grow from a leg (covered in water shoots), at a very casual angle. The legs are over 1m, but less the 10cm diameter. My pruning is rather hap-hazard for various reasons, not least that I have hard pruned, to something like a pollard, in the past, and killed more than one.
Black Knight is a slow-grower in all senses - slow to make elongation growth and slow to proliferate/divide/branch.
Ask the owner of the first for one stem, from ground-level. Strike that, trim back and graft Black Knight on the top.
My 25-year-old plants here grow from a leg (covered in water shoots), at a very casual angle. The legs are over 1m, but less the 10cm diameter. My pruning is rather hap-hazard for various reasons, not least that I have hard pruned, to something like a pollard, in the past, and killed more than one.