[MyAchingBack]

One of the more experienced allotmenteers mentioned that when he plants his cabbages and cauliflowers he always puts a little piece of rhubarb into the planting hole. Apparently the acid from the rhubarb helps the cabbages and cauliflowers grow healthily. Has anyone tried this?

[mumofstig]

It's just an old wife's tale 

have a look at this thread
http://chat.allotment-garden.org/index.php?topic=62606.msg721134#msg721134



Nothing to stop you trying to see for yourself - I wouldn't waste the rhubarb 

[DD.]

As I said in the linked threads, it's utter nonsense if you think about it. Club root does not like alkaline soil, which is why we lime it to discourage it.

Why stick something acidic under your brassicas, then?