No, they don't like frosts one bit. I lost all my collection the winter before last, so I keep mine in pots and put them under glass, in a frost-free greenhouse. as even fleece didn't save them. I shall be in trouble if they do get too big to take in! I suppose that treble layers of fleece might be OK...I think that as they mature, they can withstand lower temperatures, too, or so I've been told.