Thank you Beth but I found a sneakier place to store the potatoes - in the granny flat (in hessian sacks on a tarp). It's cool and frost free, and my aunt (not granny) doesn't use it in the winter - and what she doesn't see she won't know about

. It has worked well this winter for tatties, but I lost all the beetroot still in the ground when the hard frosts hit so early last year. (doganjo - OH doesn't like vinegar with his beetroot - prefers it freshly cooked

).
Carrots I left in the dry ground in the tunnel and most have survived very well and are still edible - just a few left to eat this weekend. Rodents didn't get them, nor frost, but a few dried out too much to use. The rest still taste wonderfully carroty

Onions just freeze in the shed. I like the tin plate idea although I think our vermin are too acrobatic for it to work 100%. I had a slightly different problem with the alliums this year in that although I dried them thoroughly in the sun, and cleaned them up before storage, quite a lot didn't make it to January as they developed mould/rotting under the skins. A few were at the necks, but mostly fairly widespread under the top layer of skin - which looked ok until I cut into them. This applied to shallots as well as onions, but not garlic which has been excellent.
For the onions, I had tried growing them through black weed suppressing fabric and I wonder if that somehow contributed to the rotting. I am doing the same this year but I will be more diligent at making sure the holes are big enough so the onions are not hiding under the fabric, rather than on top which they should be.
So, another year and another go at finding the best storage methods - I love it
