Do you cut this plant to ground level in winter or just leave it alone.

Hi Rodders,welcome to Goy. I just cut the flowering stalks back when they have finished and leave it alone. Not being far from you (on the south bank) it will be ok as it is a perennial and mine has gradually become larger with more heads each year.

And i agree aster and as i am on the outskirts of cottingham I'm even closer to Rodders.
and a welcome from me too.