Trevor Appleton wrote:
I suspect that few have tried to grow caulies under glass or polythene
over winter because of the space they take up, if you have spare space
then give it a try, look for a small variety of winter cauliflower, they
will have to be sown around May, planted into the tunnel end of
June/July so will be taking up space fpr a lot of the time you would
want the room for other crops.
I wouldn't bother

This year I've accidentally grown a pot of caulis in the greenhouse,
which are just now coming good. Due to the lack of pests and lack of
weather damage, they are looking like my best caulis ever.

Next year I'm planning* to grow brassicas up the sides of my tomatoes,
then when the tomatoes are finished, to cut them down to the ground and
leave the brassicas in situ over winter.