Success! After the main central growing portion rotted and pulled away am pleased to report the whole plant is now one mass of smaller flowering spikes, there are loads of them all lengthening by the day. Kept it covered all winter under a plastic tent and it seemed to have paid off. Only removed it around a month ago. It's perhaps not going to be as tall as it should having lost its centre, but I dont mind really! Will post a pic when it decides to bloom.

Gill.