I sow my fall/winter carrots in mid July, and mine are about 4 inches tall. When it starts to get really cold, I cover the whole bed thickly with hay, packing it in tightly around the carrots. I dig them on sunny afternoons throughout the winter, digging enough for a couple of weeks. They're sweet and delicious. If you wait until spring to dig, be sure and dig them before they start to grow again.

I do the same thing with carrots - mulch them and use them all winter. Sometimes the tops freeze, but most of the carrot is still good and much tastier than store-bought.