They have bolted this means they have gone to flower early. They can stay in the ground over winter to harvest when needed and should start to flower early spring. The reason why I am not too sure but a lot of veg seem to be bolting this year I have found two cabbages and some of my beetroot has started to go to flower on my allotment the only thing I can suggest is the weather that is causing them to stress out.

Hot, dry weather is the most common cause of bolting. Lack of nitrogen or excessive phosphate can also be a factor.