Found out about the marigolds on the compost heap!! Apparently if you chuck Tagetes Minuta (Marigolds) seeds on the heap that contains couch grass their roots contain a natural herbicide and not only do they kill the couch, but are also good at killing other bugs and pests too.....
Louisa xx
http://www.edirectory.co.uk/chilternseeds/pages/moreinfo.asp?Table=Product&RecordID=BFBCJGF
Try this link....