I tried rooting powder, scratching the bark off, coating it in rooting powder, one stem i bought gave me a run and started to shoot buds but then died, i think the energy / food within the stem caused that, you might be right about my own plant, but that is providing me with my needs for now so i will leave it be.
I shall be cutting back a bit in march to stimulate new growth, last summer which was a good one it doubled in height.