If it was a plot in the ground I would suggest 'green manure' seeds which you dig into the ground the following spring. As you don't dig raised beds this would not be a sensible suggestion!
Either leave them empty or pretty them up a bit with winter pansies or something similar.
Don't growers plant garlic in November or Japanese onions?

Yes, thanks, B, I always put Japanese onions in, but usually in October- unless you know better ? But my garlic has been very small of late so I may not bother with it this year

Get the garlic in, H, as you can't have another bad year! The strips of veg (8/10 plants) should be £2 a strip.

Thanks guys, i'll be down at the garden centre tomorrow.

i cover my beds with old carpet or black plastic till the spring, the black plastic will warm the soil quicker too.