Assuming the frosts are over in your vicinity, I would be inclined to cut away the dead stems and just keep it moist and carry on waiting. I know that some people set fire to the dead stems but it can be dangerous. My previous neighbour had a particularly large one in the centre of a small front garden; he set it alight and it nearly ended up with the firebrigade being called.

Thanks Jimmytheone, don't think I'll be setting fire to it seems a bit drastic lol. Will have to persevere with the watering. The annoying thing is that in my previous place I had a really large pampas which was growing in rubble left by the builders !!

Hi, welcome to GoY, this is 1 of the toughest plants I know, years ago I had to dig 1 out, cut all the growth off, and put the rootball on a bonfire, the fire didn't destroy it, and it sent new shoots up, I eventually had to put it into the council garden waste bin, to see the last of it, Derek.