I was given a magnificent Agapanthus (no lable attached) for my birthday in August. The flower heads are as big as my own head and it was glorious over the last couple of months. It is in a plastic pot - quite a large plant....it's starting to die down now, I've raised it off the ground but cannot imagine it is hardy as the leaves are quite wide....what's the best to do with it? Do I cover it and trust leaving it out side or put it in the shed in the dark? I have no greenhouse.....Help please??