The winter weather in my area has certainly been capricious. One day we're digging our way out the door, a week later it's mudville and then we're treated to face-freezing winds. We have the option of running indoors, but our plants don't. I'd much prefer a thick coating of snow that sticks around for awhile. (Actually I'd much prefer an early spring, but I'm being pragmatic.) All this freezing and thawing is very disruptive to plants that are trying to sleep through winter. If you live in a cold climate, mulching may not be on your list of things to do at this time of year, but you might want to rethink that.
Winter mulching makes sure that the plants you put to bed in the fall don't wake up before they're supposed to. It also helps them conserve whatever water remains in the soil during winter. Winter mulching is about keeping the ground cold, not warm. The hard part is knowing when to do it. For you lucky (ahem) gardeners buried under a foot or two of snow, nature has taken care of that for you. Here are some winter mulching tips for the rest of us.