June 16, 2017
The City of Edmonton is balancing safety, environmental, financial and social costs and benefits with new measures to address this year’s proliferation of dandelions.
To ensure the safety and usability of 1,465 sports fields across the city, a low-risk herbicide (iron chelate) will be applied. The condition of many of these fields will also be improved with top-dressing and aeration. Dandelions and other weeds on roadways and in parks will be mowed according to current practice.
The City will apply two treatments of iron chelate. While effective, it is also one of the safest broadleaf weed control options available as it dries quickly, does not have a strong odour, does not not leave a chemical residue on the grass, and poses negligible health or environmental risks. Grass growth will not be affected. Treated weeds turn a dark red-black colour, but they are safe to touch.
The first treatments will start in late June and continue through July. The second treatment will be applied a few weeks later. Fields should be avoided during spraying, but they are safe to use when dry - between 30 minutes and three hours after application, depending on weather. Signs will be posted to advise people when the fields are being sprayed.
In June 2015, City Council voted to restrict conventional herbicides on City-owned land and identify exemptions for low-risk products. Iron chelate is among the identified low-risk products. Weeds in City sports fields are now primarily controlled via top-dressing, aeration, and overseeding. Regular mowing cycles to manage weed growth and improve the appearance of sports fields will continue.