If strange mutilated plants appear, it is worth considering aster yellows as a possibility. http://www.extension.umn.edu/info-u/plants/BG447.html Aster yellows is a common plant disease that affects a wide range of flowers. Aster yellows is caused by a tiny organism known as a phytoplasma and is spread from plant to plant by leafhopper feeding. Ontario Agriculture Factsheet. http://www.omafra.gov.on.ca/english/crops/facts/98-057.htm
