Posted: 18/03/2012 at 20:48
Likely to be slugs and snails, try sprinkling bran around for an organic alternative,or salt as a quick measure although this wont have lasting effect. If its indivual specimen plants you want to save, try a copper ring, they hate copper. If its not snails, check underneath your leaves for caterpillars and pick off and destroy, or rub off aphids if present, soapy water or boil rhubarb leaves to make an insecticed and spray.