Mine is too and that is fine. if you do cover it you will get early 'forced rhubarb'. tasty but you can only harvest about 1/3 to 1/2 of the stalks then you need to leave it to grow in full light.

I tend to force mine every other year.

Nothing wrong with rhubarb in December. Enjoy it. All I can grow is popsicles & icicles. Icicles.

Thanks for the replies, only just found them, growing well now, H.