Just cover them with about six to eight inches of straw or oak leaves. I use the oak leaves, since they're free, abundant, don't rot or pack down like most other leaves. You may want to throw some mouse bait blocks down if you have rodent problems.

The carrots will do just great all winter. You can dig as needed over the winter if the ground isn't frozen. They are at their absolute best flavor and texture as soon as the ground thaws first thing in the spring -- extra juicy, crisp, and sweet. So good, in fact, that I think someone should develop a way to market them as a special, gourmet treat -- call them 'Ice Carrots' along the lines of the 'Ice Wine' that is harvested from the frozen grapes in very late fall.

Thank you for the response I don't have any oak trees around but I can get ahold of straw pretty easy. Will it hurt the carrots if the ground freezes?

Dennis gave you good advice but let me reinforce a point: if you get voles in there there will be trouble. I have, many times. Eventually I developed a strategy of covering just before the ground freezes (in MI, that will be another 7 weeks). Not 100% foolproof, but much better. The later you can cover, the lower the chance they can move in. They won't tunnel through frozen ground. I also keep compost (kitchen scraps) far away from the garden. That helps by concentrating them elsewhere. Straw is as bad as leaves.

I have hoophouses and I have discontinued the leaves but follow similar practices now, that is, cover the beds as late as possible. The hardy leafy greens do not suffer much, and the mice are not as many.

If you know that it will snow a lot, you don't even have to cover with leaves. Snow is a pretty good insulator. The term "snow farming" means digging snow from the paths, and piling it onto the beds for thermal protection. It does not attract voles like leaves do. Last winter was very cold here, but with good snow cover, the ground never went below about 30F. For overwintering root crops, that is ideal.

I trenched in some stainless steel mesh to try to keep out voles. We'll see how it does this winter.

glib, will they run over or near the surface of the snow to get over a barrier, or do they pretty much stay at ground level? I'd like to find out if a barrier extending 2 feet above ground (and trenched well in under ground) is enough, or if I need to stomp down the snow around it if the snow drifts up a few feet.

What are voles? Are they the same thing as moles? We are suppose to get snow on Sunday so maybe I will try the tip about piling the snow on top.

Voles are NOT moles. Voles look like fat mice with short tails. They eat plants. Moles have large "hands" on their front legs for digging and they eat earthworms and other invertebrates.