Until yesterday, when I noticed my Nasturtium was covered in Cabbage caterpillars, I had no idea that they particularly liked muching away on it's leaves. I then read about growing Nast.as a companion plant to Cabbages (which I have at the allotment) to tempt the Butterflies on to the Nast. instead.
I'm slightly confused though as wouldn't growing both increase the number of Cabbage Butterfly & caterpillars overall on the cabbages? Or is it a case of using the Nast. to tempt them in so they can be, ahem, dealt with?