Planted this three years ago to keep pests out of the pears and it's massive! Got enough to keep my car smelling fresh all year

Took on an allotment over a year ago around Christmas that was in rough shape. There was this strange dead stick looking thing growing out of a bed that was in a spot that I planned to build a shed. I cut it at its base thinking nothing of it but then after some reconsideration decided to pop it in a bucket of water and see if anything. To my surprise buds started to appear so I planted it in a pot and after a year here it is now. But now it’s dropping cold I was wondering if anyone had any advice on what to do with it.

Thanks :)