Just because its December and we have had some snow doesn't mean the Allotment goes quiet at this time of year. There is plenty to be getting on with.
Assuming you had a good year so far there will be plenty to harvest:
Winter cabbages, cauliflowers and the Brussels sprouts can be harvested now. Remember Brussels are not just for Christmas :)
Leeks should also be just about ready, just take what you need and leave the rest to stand until required. Leeks are much better harvested from the garden as they are required but in severe weather this can be difficult, so you can lift a few and heel them in on well dug ground, this will not freeze solid.
Carrots can be lifted now for storage if you haven't done this already, they can be stored either in peat or sand or even a traditional clamp.
Jerusalem artichokes should be ready for harvesting now and you can also start on salsify and scorzonera. Salsify is known as the 'vegetable oyster' and is a wonderful vegetable when it has been cooked properly.
Lift celery, parsnips turnips and swedes although parsnips and swedes are very hardy and may be left if the ground is you are not yet ready to eat them. You can always cover them with fleece or straw to help stop the ground freezing them in.
Finally you should check the vegetables you already have in storage and remove anything that has started to rot before the rot spreads and ruins the entire crop. Potatoes in particular should be checked regularly and watch out for slugs that have emerged from a potato to go and damage another one.
Other jobs to think about, Cleaning the greenhouse or coldframe if its empty over winter, check and repair any broken fences, sheds etc. December is also the ideal time to prune apples and pears as well ass gooseberries and currants.Clean, oil and repair your tools, its amazing how much they get used over the year so will appreciate some TLC in December.
But whatever you do remember to stay warm, and be careful on frozen ground.