SUNDRE, Alta. — It’s a dainty, yellow flower, but tall buttercup is no shrinking violet.
The plant has become one of the worst weeds in western Alberta, choking out grass and infesting thousands of acres of pastureland.
It’s estimated tall buttercup has infested 10,000 to 15,000 acres in Clearwater County alone since it first hit the radar in the 1980s.
“It’s spread across the county at an alarming rate,” Kim Nielsen, manager of agricultural services with the county, said during an agricultural tour.
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The perennial plant isn’t a serious problem in annual crops, but it has taken hold in the rolling hills and trees of Clearwater County along the foothills of the Rocky Mountains.
It likes moist but well-drained organic soil, which is plentiful in the county.
“We’re winning the battle against tall buttercup but we’re losing the war,” said Matt Martinson, assistant manager of agricultural services.
The county spends hundreds of thousands of dollars a year spraying roadsides and ditches in an attempt to control the weed on county land. Modified spraying equipment helps sprayers travel over the wet and often rough land where tall buttercup has settled.
“Tall buttercup and wild caraway are two weeds that cost producers in this county more than any other plant or pest issue,” said Martinson.
Spraying and cultivation are the two main ways to control the weed, which is spread by seed. Each plant can produce up to 250 seeds.
Al Tink of Condor, Alta., blames the tall buttercup, which is poisonous, for lameness in his Canadian horses this spring. It contains a bitter, irritating oil that causes blistering on the skin, mouth and digestive system and is particularly poisonous in cattle.
An intensive spraying program has helped control the infestations, especially around water sources on Tink’s farm, but he has been diligent in trying to eradicate the weed.
“Al is a weed warrior,” said Martinson.
However, not all farmers, ranchers and acreage owners in the county are as diligent.
It costs $20 to $ 40 per acre for chemicals, plus the time and spraying equipment costs.
“It’s not cheap to remove this plant from the pasture,” said Martinson.
Allan Sundae of Leslieville has worked with the county on a grazing trial to study pasture losses from tall buttercup. Grazing data from a trial near Alhambra, Alta., showed that the economic losses can be as high as $23 per acre for loss of forage.
Twenty pairs of cattle were placed on pasture in the second year of Sundae’s trial to intensively graze the grass, including tall buttercup. The cattle didn’t avoid the tall buttercup during the intensive grazing project.
“The cow doesn’t have time to be selective,” said Sundae, who believes intensive grazing is another tool that can be used to control tall buttercup.
“I’ll stand and watch sometimes and there are places the plant is one foot high and the odd heifer will lap it back and suck it down.”
Cattle will avoid eating tall buttercup without intensive grazing.
Nielsen believes the poisonous effects of the plant increase as the plant matures.
“We’re speculating that’s why the cattle devoured it when they did,” he said.
The tall buttercup couldn’t compete with the grass because the pasture has historically been left as stockpiled grass to be grazed in late fall or early spring.
Nielsen believes the tall buttercup may muscle out the grass as the pasture is grazed more.
One of the county’s eradication efforts is the Priority Area Weed Compliance, a community driven program that encourages landowners to take part in tall buttercup control.
It is modelled after an Australian weed control initiative and includes a steering committee that allows landowners and county staff to work together to control the weed.
The program achieved 100 percent compliance at the end of the first year from the 148 landowners on the 200 parcels of land within the project area.
“The whole community says, ‘we want to get rid of buttercup,’ ” Martinson said.
“We’re driving it, but it’s a bit of a way to use community spirit, community pride and peer pressure to do the same things and we’re fostering a weed control program.”
He believes including landowners in the weed control program increases the chances of keeping the weed out of the rest of the county’s three million acres.
