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Noxious weeds invading Summit

Jane Stebbins

EDITOR’S NOTE – This is the first in a series of five articles addressing noxious weeds in Summit County. National Weed Week is July 13-19.

SUMMIT COUNTY – Weed warrior Paul Schreiner is fighting a battle that’s here to stay.

Every day, he scours the land for the prickly leaves of Canada and musk thistles, the stout common mullein, yellow toadflax, diffuse knapweed, the delicate purple field bindweed and many other weeds that have a toehold on the Summit County landscape.



“We’ve made a lot of progress,” the Summit County Weed Program coordinator said. “But some of our weed problems are here and here to stay.”

Many noxious weeds were brought here by immigrants who wanted something to remind them of home. They have since moved – on the wind, in the hooves of animals or feet of hikers, on the wheels of cars – into areas they’ve never been seen before.



They force out native plants, usually because they have no natural predators to keep their spread at bay. Once they take root, they are difficult to eliminate. In worst-case scenarios – seen in numerous locations throughout the West – they have created a monoculture of weeds, which results in a loss of insect, then rodent, then predator, life.

Since Schreiner started his fight three years ago, he has located, identified and, in some cases, controlled infestations of noxious weeds throughout Summit County. Treatment runs the gamut from weed pulls like the one scheduled for Dillon Saturday, to weed-eating goats and insects, herbicides and mowing.

For instance, in 2000, Schreiner treated 18 acres of land along the Dillon Dam Road for false chamomile, musk and Canada thistle and oxeye daisy. Last year, he only had to treat two acres.

He also has managed to reduce the musk thistle population along the bike path between Dillon and the Dillon Nature Preserve by 95 percent.

And a herd of goats Schreiner arranged to munch weeds around the old and new Dillon reservoirs has cut the thistle population there dramatically, he said.

Early summer rainfall has also helped revive native plants that were weakened by last summer’s drought.

Technology on the horizon involves robots that detect weeds and inject into them a chemical that sterilizes the plant and robots that can determine whether a weed should be pulled, dug up or sprayed.

“The more we bring to the weed problem, the more people wake up to what’s going on, the more resources we can throw at the problem and the more results we’ll have in the long run,” Schreiner said.

But with every victory, comes frustration.

Leafy spurge, one of the worst noxious weeds to debut in Summit County, has made headway in new locations in Wildernest, in Frisco near the Dillon Dam Road and in Copper Mountain. That plant’s roots can extend 30 feet deep and creep under the ground.

Schreiner said he’ll have to treat a 1,000-square-foot area for the next 30 years.

“It’s that hard to get rid of,” he said. “We’re harassing it in every shape and manner that we can to keep it from spreading, but at the same time, we’re finding new infestation spots.

And there’s musk thistle, a relatively easy weed to manage – except for the plant’s seeds, which can live up to 20 years in the soil.

“It’s a lot of work to knock it back,” he said. “And then you have to go back for 17 years to make sure it’s not re-emerging.”

North of Heeney, he was working to eradicate a population of field bindweed when another six infestations popped up along Highway 9.

Most recently, Schreiner has found spotted knapweed at the fruit stand in Silverthorne and a new infestation of hoary crest in Breckenridge.

“We’re on the front line of the wildfire,” he said. “And we’re having all these spot fires show up. We’re surrounded by these plants and they’re moving in. We’re being bombarded.”

Education is starting to have an impact.

“It’s somewhat disheartening to see new species come in,” Schreiner said. “But people are reporting them, so we can react to them. Early detection is key.”

Schreiner, however, is always looking ahead – like, 100 years ahead.

“I don’t see things so much in today,” he said. “I see things in 100 years. I want some magic potion that’ll automatically make people look at the world through my eyes and see what’s going on. If they did, they’d be scared silly. It’s spooky; over the past 200 years the number of extinctions we’ve seen through man’s actions. It makes the extinction rate the dinosaurs experienced pale in comparison.”


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