Guelph’s weed experts agreed autumn presents a great opportunity to prevent the spread of the yellow scourge.
“Now’s a perfect time to be overseeding,” the city’s healthy landscapes technician Karen McKeown said Friday, adding the extra seed would give grass a head start over dandelions come spring.
Francois Tardif, associate professor of weed science at the University of Guelph, said dandelions germinate this time of year. “We just don’t see them in the fall because they are tiny,” he said.
Killing the plants in fall means stopping them from flowering and spreading their seeds.
Guelph residents have come to view dandelions as a serious nuisance since the province introduced a ban on residential pesticides last year and some parks were overrun with the plant.
“There were fields that were completely covered,” Alan Gould, executive director of Guelph Soccer, said Friday.
“Grass cuttings became entangled in the dandelions, so there was a matting effect,” he said, adding parents feared their children would trip over the green knots.
Guelph resident Rita Zolnai lives across from St. George’s park, which became infested this spring. “The park’s terrible. They’re not puttin’ nothing on it,” the 84-year-old said Friday. “It’s a pain in the neck.”
“I got a lot of dandelions. I can’t get ahead of it,” she added. “I dug out a lot. Some I did by hand.”
McKeown said residents will have to get used to the extra work.
“We’re calling it the new aesthetic,” she said. “We’ll have to get used to dandelions. They don’t really do any harm, and they’re only up in the spring.”
McKeown said research proves pesticides are harmful to humans, adding “you don’t know what it’s doing further down” to soil and groundwater.
Is it really worth using dangerous chemicals “just to kill a dandelion?” she asked.
At the Guelph Turfgrass Institute, Tardif is currently testing the efficacy of organic alternatives. He said he’s not convinced they are any better for the environment, since most must be applied more frequently and heavily,
“The alternative practices have an alternative environmental impact,” he said.
Organic weed control will also require “much more effort to achieve the same results,” he said.
In the past, the city hired a small army of 100 students to aerate, fertilize, overseed and irrigate the city’s parklands every 10 business days.
Tardif said the city maintenance costs would rise unless people adjust to parks and lawns that don’t look like Florida golf courses.
McKeown admitted organic pesticides are often more finicky than their high-impact cousins.
Vinegar-based herbicides, for example, will “kill everything” if applied too heavily, she said. Sarritor, a fungus that kills broadleaf weeds, only works under specific weather conditions.
But McKeown said dandelions and other weeds would not go away, with or without chemical pesticides. “Weeds are opportunists. Any kind of bare spot you have in your lawn, the weed seed will germinate.”
She said Guelph residents are adapting to pesticide-free lawn care, crediting the city’s free landscape assessments.
“That’s really helped people overcome the pesticide issue. We can see any problems they have, and give them advice,” she said.
In the meantime, Guelph residents might do well to heed the experts’ advice and do a round of overseeding and fertilizing before winter.
Tardif said the wet summer of 2010 likely made the dandelions germinate earlier, meaning next spring’s yield could be bigger and “more vigorous.”
“You’ll check next May. It’s going to be quite the year,” he said.