Colorado Weed Control Agency
Turns To High-Tech Approach

By David Bowser

DURANGO, Colo. — The brightly colored yellow flowers cover the hillsides in pastoral serenity, or so it would appear. But appearances conceal a battlefield, where the flowers and the weeds that produce them are aggressively crowding out native vegetation and destroying grazing.

"Non-indigenous ornamentals have come in here and spread like crazy," says Rod Cook, La Plata County weed specialist. "We have some pretty tough weed species that happened to have come in here in the last 20 years."

The problem is not just in southern Colorado.

"It's typical of the whole West," Cook says.

Typical is the oxeye daisy that has spread across the Rockies.

"The oxeye daisy is one that we're really concerned about," Cook says of the pretty yellow flowers that are showing up increasingly on the hillsides and along the roads here. "It's really eating up our mountains up here. Nothing eats it."

It extends from Colorado to Canada, British Columbia, all through Wyoming, Montana, Utah, and New Mexico.

"We all have pretty much the same weed species problems," Cook says.

He says that on his last trip through the Texas Panhandle, he noticed that musk thistle was starting to establish itself on the west side of Amarillo. A friend of his near Lubbock reports spotted knapweed on the Texas South Plains.

"There's camelthorn," Cook says. "It's taken over Crested Butte."

There are also weeds that are poisonous to livestock and can affect them negatively.

"Certainly, you've got Russian knapweed that is poisonous to horses," Cook says.

But poisonous plants are less of a problem than what cattle and horses aren't eating.

The leafy spurge, spotted knapweed, yellow starthistle, St. Johnswort, Canadian thistle and purple loosestrife have invaded millions of acres of rangeland, undermining plant diversity and leaving the cupboard bare for herbivores, both domestic and wild.

When a Montana rancher, in a 1987 study by University of Montana researchers, killed spotted knapweed with herbicide, the grass increased from 48 pounds per acre to 1620 pounds per acre, improving the ranch's carrying capacity 20-fold.

In an effort to bring these and other weeds under control, Cook and his two assistants have launched a battle for the pastures and fields of La Plata County.

Using a Geographic Information System, or GIS, they start by mapping the location of each patch of weeds in the county. They then notify the landowner of the type of weed and what can be done to control it. But in a region with a growing number of absentee landowners, it is still a difficult problem.

His office has built a database of landowners in the county in the computer system that uses space age technology to plot the locations of weeds.

Their computer program shows not only the location of the weeds on the land and the landowner's name and address, but it also shows, in color coding, the type of weed in each location.

"We're pretty much leading the way in GIS weed mapping," Cook says. "We're kind of ahead of the rest of the West. There are a couple of other counties starting to use it, but we've been doing it for four years."

They can generate a map for any area, including subdivisions, Cook says, adding, "We have over 300 subdivisions in this county."

From their map they generate a mailing list, notifying landowners of the types and density of the weeds on their land. Each week Cook and his crews are out mapping the location of weeds in the countryside.

"They map the whole county every year," Cook says. "That's what's really nice about this mapping system. We're able to do the whole county every year."

He says for the tax dollars spent, they may well have one of the more efficient programs in the state.

"Friday morning we come in," says his assistant Walker Mitchell, "and tell the computer to merge all the data to make mailing lists. Then we write a letter and put the mailing list with the letter and mail all the letters right after noon. We're mailing out 200 letters a week sometimes."

"We have a lot of absentee landowners," Cook notes. "You just look at this database and it's amazing where people live. I mean, they're all over the world — Japan, Europe, Canada, all over the United States. There's no telling where all we've sent letters."

He says they may come to Colorado to ski for a week in the winter or have a vacation home here, but they may not know what vegetation is growing on their property.

"We feel like we're kind of the cutting edge of noxious weed management," Cook says.

Historically, Cook explains, if people didn't manage their weeds, Colorado weed control districts gave them a 10-day notice, then took county spraying trucks in and sprayed the weeds, adding the cost to the property tax bill plus a management fee of 20 percent or so.

"We kind of feel like that's not the slickest deal going," Cook opines, because the county can be held liable if a well is polluted or a tree is accidentally killed by the spray.

"Even if they said you did and you didn't, it would still take years in court to figure it out," Cook continues. "We feel like we want to give landowners a choice."

So Cook's office sends them a letter saying his inspectors have seen a certain type of weed on the landowners' property, and the landowner can take responsibility for it and manage it or pay for the impact.

"It's their choice," Cook says. "They can choose either way, choose not to manage the vegetation. That's fine, but it's going to cost them plenty for the spraying, and that money will go right back into our weed program."

State legislators are working on a law that would add a 10 percent impact fee onto property taxes the first year for those not managing their weeds.

"It will double the next year and then double again the next year," Cook says.

Consequently, property taxes for Colorado landowners could go up 40 percent for those who fail to take care of weeds on their places.

Cook says La Plata doesn't have any spraying equipment.

"All our spraying is contracted out."

Cook says the system works best when the landowner takes care of the problem when he is first notified. Otherwise, the paperwork multiples and there is a good chance the plants will seed before they can be controlled.

A lot of people moving into the area don't want anything to do with any chemicals, Cook says, whether it is for weed control or not.

"We don't care," he says. "I don't care if they go out and hand pull them or mow them, as long as we don't see the weeds. That's fine with me. We just don't want them spreading to the neighbors."

Some of the weeds, however, will spread even if they're mowed.

"Yellow toad flax is real aggressive," Cook explains. "We've seen it get into some turf areas, some lawns. It's a big rangeland weed deal. It's eating up the mountains."

White River National Forest near Meeker, Colo., he says, has more than 125,000 acres of it now.

"Nothing eats it," Cook says. "It's crowded out our native plants and grasses."

It even crowds out other weeds.

"We've got some weeds like Russian knapweed and yellow toad flax that will crowd out leafy spurge or the thistle groups."

It will directly compete with other weeds in addition to indigenous plants.

"It will go in there, invade the site and then crowd it out," Cook stresses.

To increase awareness, the weed district has put out calendars and gimmee caps.

"Montana did a noxious weed calendar," Cook says. "We thought as a state weed association we'd better do one, and it's been popular. It's gained support for our Colorado weed programs."

He says they've had good results in working with both ranchers and environmental groups.

"Anytime you get some of these weed species that come in and have the ability to invade grass rangeland," Cook says, "then you get your tonnage per acre reduced and maybe replaced by a weed species that's either not as high in protein or doesn't produce as much forage, as many tons per acre."

The cows can probably still make it on some of the weeds, he says, but it's not the best thing for them.

The challenge is getting support from all the different groups with which he works.

"We work with the most diverse cross section of society here," he says. "We've got everything from trust fund kids who move here with tons of money to people who have worked in big cities all their lives and want to retire here on five acres of land, to ranchers."

He says they have horsemen and outfitters going out and spotting weeds for them in the back country.

"We have several environmental groups," Cook says. "We've had real good support from the environmental groups."

They even sprayed a nature preserve in cooperation with one environmental group.

In addition to the individual groups of people, Cook says they work with different soil and water districts, municipalities and associations. They have 11 counties in the area working together and pulling in grant money to combat the weeds.

"We get grant money every year for different projects," Cook says.

They receive money from the U.S. Fish and Wildlife Service, the U.S. Forest Foundation and the Colorado Noxious Weed Fund.

"We started our program here in 1992," Cook says. "We'd never had a weed program here. We started with nothing. Through necessity, we got to where we are."

At one time, they were going out with pin flags and writing on them with markers what different types of weeds were out in the country, putting their weed office phone number on the flags.

"We'd stick those over the fence on a landowner's property," Cook says. "That was the way we first started notifying people."

He says it was a simple system, but it worked.

Now, with the high-tech systems they have, they're trying to figure out how to move faster than the weeds. Using their GIS computer letter notification system has helped meet that need.

"We sent out our first letters last year," he says. "I guess we sent out about 2000 letters."

Herbicide sales at the local co-op jumped 47 percent that year.

"It went from $245,000 in 1997 to $360,000 in 1998," Cook says. "This year, they say they've even surpassed that."

During the winter, they hold classes to show people how to use herbicides safely and improve grazing practices. They hold a weed symposium in the spring.

"What has really worked for us is demonizing weeds to every group," Cook says, "because weeds affect everybody. We just have to figure out how weeds affect that group, then hammer on that."

"Anybody who owns land in Colorado," Cook says, "we're going to ask for their support and for them to become educated and not let the weeds spread."