Can someone help me please, I searched high and low for a bottlebrush like the one my mother had that the council destroyed. Found it CALLISTEMON rigidus.

I planted it last year, along with a smaller more plant like bottlebrush and covered them over our horrible winter as she had told me they would not cope with the cold until it was a few years old.

The weather has finally picked up and I've removed the "breathable, protective" cover, all the leaves are brown, and covered in mildew spots, the thing looks dead. However, the end branches are still very pliable when you bend them, so it makes me think the plant itself isn't dead.

I know you can prune them, but to remove all the dead leaves, I'd have to cut it right down to the ground.

I've spent so long looking for this plant, and now I'm scared the -14C weather has killed it.

Can anyone give me any advice?