Darren that is disappointing, funnily enough I was harvesting some nice (if small) ones this evening, variety Pixie, and noticed some others (Pyramid) with smaller hearts looking as though they are thinking of shooting upwards…. I think it is stress from drought, and perhaps the heat, together with a varietal tendency and I have not grown the one you mention. So you have a lot of cabbage to eat now! Frustrating after waiting for over seven months!
Ladbrokes it is normal for kale to flower now (Brussels too if there are any left) and all shoots are good to eat.