Workers in Lanark County, Ont., have been experimenting with some alternative methods to curb an infestation of noxious wild parsnip after some landowners raised concerns about spraying chemicals on their properties.

On Tuesday a crew of four county employees were busy digging up, weed-whacking and mowing wild parsnip stalks along one 50-metre stretch of rural roadside, and CBC Radio's Hallie Cotnam caught up with them for Ottawa Morning.

"We're just doing a trial here to try to get a handle on how much time it is going to take to do areas in this manner. We've got 560 kilometres of road," said Terry McCann, the county's director of public works.

Bags of the noxious plant are left in the sun for a week, and are then safe to dump in landfills. The workers have to wear long sleeves, protective glasses and thick rubber gloves to protect themselves from the plant's sap, which causes burns when it's exposed to UV rays.

McCann knows what that's like — it's happened to him.

"You get large blisters on your skin. You feel a burning sensation as the UV rays hit it. It usually takes an hour or two, you'll feel a burning sensation, and then you'll get large blisters on your skin, two inches across, and they'll come up as much as a half an inch," he said.

Here's a close-up of some flowering wild parsnip before it seeds. (Hallie Cotnam/CBC)

'Has to be dealt with'

The municipality estimates that about 40 to 50 per cent of its roadsides are infested with the invasive weed, and that there are some other sections with lighter infestations.

In infested areas, McCann said the most time- and cost-effective technique to kill the weed has been spraying it with herbicides. Mowing it down also works, but it takes more time, a lot of trucks, and has the downside of killing every other pollinator-friendly plant, such as wild daisies and milk weed.

The county doesn't have enough workers to eradicate all the plants using such time-consuming methods as weed-whacking, mowing and digging up roots, but McCann hopes an adopt-a-road program could attract volunteers to help out.

Landowners could also start mowing the roadside allowances in front of their properties to help the municipality, McCann said.

"It has to be dealt with in some way, and that's what we're in the process of doing, is trying to find out the best ways to control it," he said.

Listen to more from the crew here.

Terry McCann, wearing the white hat and blue shirt, and his crew. (Hallie Cotnam/CBC)

One of the crew members uses a weed-whacker to cut down parsnip along the side of a road. (Hallie Cotnam/CBC)

The crew have to wear protective gear, including thick rubber gloves, to handle wild parsnip stalks. (Hallie Cotnam/CBC)

The crew hunts for wild parsnip. (Hallie Cotnam/CBC)