Only hardy vegetable types can remain outdoors
Vegetables such as lambs lettuce, spinach, winter onion, leek, Brussel sprouts and curly kale can remain on the beds in winter. While lambs lettuce continues to grow in mild winter temperatures and therefore should not be covered, it is a good idea to give vegetables such as leek some frost protection. You can easily harvest and store root and tuberous vegetables in a cool, damp cellar room, preferably at approx. 5° C. Storing in the same room as fruit is not recommended as vapours from fruit significantly reduce the storage life of vegetables.
If the vegetable bed is already frozen, you should not touch or harvest the vegetables as tissue damage may occur even at the lightest touch and lead to rotting.