One of the first poetry books I ever bought was Sylvia Plath’s Winter Trees. I didn’t understand much of it, but one image has stayed with me all these years – her description of trees dissolving in the fog like ink on a blotter. On foggy days, I love savouring the ease with which trees simply evaporate into thin air. But winter trees don’t need fog to put on a show. Before Christmas, sharp frost turned one of my favourite birches white with ice crystals. Usually black and brittle, the branches and twigs were like a frozen fountain.