Brassica

Lately, one spot in my garden has been affected by possibly ‘clubroot’. I have been advised to plant different veggies there and/or spread dolomite lime. Is this correct?

My broccoli never produce heads but going straight to seed. I tried planting out in summer and this year planted into early autumn but still the same problem. What’s going on?

Earlier last year I planted 6 mini cabbages and they grew beautifully and looked nice and solid but when they were cut open they had all gone to seed, can you help? 

I recently planted broccoli and cauliflower plants side by side. The broccoli is looking very good but the cauliflower plants have died off. The roots may have been eaten by something. Can you help?

I have an 8 year foster boy who loves gardening. It's May and I bought him broccoli plants; he wants to grow them for his two rabbits. Did we plant them too late?