I have an allotment on which I intend to grow cabbages. Is there anything you can get to prevent clubroot? All the Garden Centres that I ask tell me that most products habe had to be withdrawn.

Hi Dave,
First you need to ask other plotholders if they know if your plot suffered from club root in past. Not all plots on the same site get it. Mine does not have club root but my neighbour's plot does. Once you have it, it may last for 20 years.
He grows his Brassicas on to a large size in large individual pots so that they are strong ( about 9-12") when planted out and he now grows resistant varieties but he still has mixed success.
You should check which other plants are brassicas like wallflowers, turnips, swede, kohl rabi, sprouts, broccoli and some weeds. Always treat their roots with suspicion and do not compost them. Don't let other people put stuff on your compost heap in case they infect it and don't accept any plants grown in the soil from an infected plot.
If you google 'club root' you will come up with all sorts of wierd ideas like using rhubarb leaves when you plant out but the general feeling is that it is difficult to get rid of once you have it