Tin foil trick

Before you plant you brassicas rap tin foil round from the root ball to the lower leaf not to tight allow four or five turns to stop root fly I have done this and it seems to work.
I read it in an old gardening book from the bbc gardeners question time .
It may be a little extra time spent planting out but as I have said it works.
John

That does not work!

If you stop to think about it, you lime (alkaline) to assist against club root. Why go and plant something acidic, then?

Even if it did work i like to do the allotment as cheaply as possible and foil is a little expensive to be used like this

I agree with the sentiment, but T*sco's value foil is only 90p