I grow the club root resistant varieties of broccoli, cauliflower, sprouts and swede, just to guarantee some sort of a crop. I then fill in with varieties that I want to try, and make sure the ground is well limed, plus I grow the plants on in at least 3"-4" pots, and then just put a dusting of lime around the planting hole when I put in the substantial plants. I have found that Candid Charm cauliflower does well, despite not being club root resistant - just ensure the ground is well limed about a month before planting, and a dusting is applied to the plating pocket when putting the young cauliflowers in.