The winter salad leaves I've been growing in my balcony boxes have held up surprisingly well, despite being covered in drifts of snow for the best part of a fortnight.
It's not the cold that's got them, it's a daredevil squirrel who I caught chomping his/her way through the crop just before Christmas. I say daredevil, as I live in a block of flats, on one of the higher floors. When I chased the little bugger off the balcony, mid-munch, s/he simply shinned down to the ground and scampered off.