Municipalities don’t need toxic pesticides, study finds

Maintaining attractive, functional parks and sports fields doesn’t have to cost the earth

October 2018 – A report from the Canadian Association of Physicians for the Environment (CAPE) refutes the myth that the cost of municipal weed control spirals upwards — and weeds run rampant in public parks and green spaces — when local governments are not allowed to use conventional toxic pesticides.

Some municipalities in Manitoba have expressed fears of skyrocketing costs and a virtual dandelion apocalypse, because of the province’s restrictions on non-essential uses of pesticides, which came into effect in 2015. The Association of Manitoba Municipalities has indicated that its members want the law changed to allow local governments to use currently banned products. But the study prepared by CAPE, based on information from practising weed program managers, found that the riskier pesticides are simply not needed.

City Hall, St. Catharines, Ontario

In the summer and fall of 2018, CAPE conducted interviews with parks managers in six municipalities across Canada — London, Guelph, St Catharines and Toronto in Ontario, Richmond, BC, and Cape Breton Regional Municipality in Nova Scotia. All cities that participated in the study are operating under either provincial or municipal restrictions on non-essential uses of pesticides on lawns and gardens. Some regulations have been in effect for more than 10 years.

The study found that satisfactory levels of weed control can be readily achieved at reasonable cost without the use of prohibited pesticides. How is this possible? Instead of relying on pesticides to suppress weeds, parks managers in these cities have adopted horticultural practices aimed at building and maintaining healthy turf to encourage desired plant growth and discourage weeds. These measures include mowing, aerating, fertilizing, overseeding and top-dressing.

In brief, parks managers who were interviewed for the study reported that:

• Alternative practices that focus on building healthy soil and turf are effective in controlling weeds, even on sports fields that require maintenance under demanding conditions of use.
• The cities’ weed control costs have not escalated, but have remained stable. Parks managers reported that priority green spaces of higher use and visibility can be maintained in well-groomed, attractive and functional condition within available budgets without using the banned pesticides.
• Community residents appear to be satisfied with methods of weed control that do not expose people to toxic pesticides in parks and on sports fields. Managers reported that complaints are minimal.

Cities and towns that are resisting bans on non-essential uses of pesticides, like some in Manitoba and Alberta, can take heart from the experiences of their peers in other municipalities, who are successfully controlling weeds without using the riskier pesticides. The complete report — Municipal Weed Control: Lessons from Ground Zero — is available on CAPE’s web site.