found clubroot today!

Clubroot is not nice but you can still successfully grow brassicas.  It's possible you had clubroot all along in hot spots, and not to mention you walking over the plot and tools you used to spread it around - it's not a disease carried by animals but a soil borne one.

Grow your plants (cabbage, caulis, brussels, broccoli etc) in pots of compost so that they already have a healthy root system.  When planting out, put some horticultural lime in the planting hole to raise the soil pH.  For something like radish which you can sow direct, rake the lime over the bed and water in.

You'll never truly get rid of clubroot but you can reduce the problem by not composting the roots of brassicas.  Some weeds carry the cycle on so keep the plot weed free.  And you can also try growing clubroot resistant variety brassicas too.

See DD's advice here:
http://chat.allotment-garden.org/index.php?topic=70500.msg804879#msg804879

Hi Mum,

I do not think I have club root as I have not seen any sign in the three years I have had my plots, but how would I get it? is it just from soil from other plots or could I get it from seed?

From other posts it is not something I want so I would like to know the best way to protect my plot.

Seed is ok, the fungal spores are in the soil, which you can carry from dirty soil on boots and tools, or as explained on transplants

The resting spores of clubroot, can survive passage through the digestive tract of livestock. Spreading of manure, from livestock fed with infested crop debris, could enable resting spores to be spread to areas free of P. brassicae spores.

quote from this webite  http://www.gov.mb.ca/agriculture/crops/diseases/fac63s00.html

Thanks Mum, interesting read.  I have been very wobbly about horse manure with all the scares about the weed killer so now I will keep off the cow manure also.  I have two large compost bins which I will keep relying on in future.