Apply a weedkiller designed for tree stumps. It normally comes as crystals that you heap on each freshly cut limb. Then cross your fingers!"

I use a liquid stumpkiller - you usually drill holes with a medium woodbit into the stump, fill them up with the liquid, cover and leave to die back.

you could just put some black polythene over it and cut the odd stem of that tries to grow . it worked for me .