Roots in February

With February comes the snow and icy temperatures so low, that retreating to the greenhouse becomes more of a chore than a pleasure. I have a week to sow roots, but with the weather so cold it looks as though my main root sowing will have to wait now till March!
This is what I had planned:-
-Leeks
-Spring Onions
-Beetroot
-Carrots
-Potatoes in tubs
-Horseradish
-Celeriac
-Hamburg Parsley
-Parsnips

This is what I have sown and don't hold out much hope for:-
-Carrots in a pot (fleece covered)
-Beetroot in modules

Updated - pictures of the beetroot in modules 5/3/12