If I applied a granular herbicide containing 2-4D, mecoprop and dicamba to a lawn this fall, would it be safe to turn over part of it in the spring and use as a flower garden?
Thank you for contacting the Toronto Master Gardeners with your inquiry.
As of April 22, 2009 Ontario passed a law banning the cosmetic use of pesticides. The Cosmetic Pesticide Act defines cosmetic as “non-essential.” This term generally refers to pesticides used to improve the appearance of lawns, gardens, trees, and other aspects of landscaping. Under this law homeowners cannot use Class 9 pesticides/herbicides to kill weeds or insects on their lawn. The chemicals in your list are all considered class 9 pesticides. Class 9 pesticides are banned for cosmetic purposes because they may pose an unnecessary risk to human health, particularly children’s health. Please refer to the following website for a comprehensive list of banned pesticides: https://www.ontario.ca/page/pesticides-home-lawns-and-gardens
A more organic way to go about killing the weeds in your lawn is to employ a method called solarization. You may wish to refer to two of our earlier posts which give detailed information on this technique: