Rod Cook, who has worked as La Plata County’s weed manager since the early 1990s, thinks of himself as a public servant, not a celebrity.
Yet at this week’s Four Corners Weed Symposium, the 21st annual, where several local professionals notable for their work in the weed-fighting world spoke at the county fairgrounds, Cook was greeted like a rock star.
Almost 50 people sat rapt as he spoke about the effects of drought, warning that native species struggle with the lack of water, thereby triggering rampant weed growth.
While Cook is cautiously optimistic that the drought may soon end, auguring an advantage for native species and grass, the terrain on which the broader war on weeds is fought will likely remain hostile.
Weeds are a huge problem throughout the world and in La Plata County. Internationally, they are responsible for a 10 percent decrease in crop productivity. In the U.S., weeds do $33 billion worth of damage to the national economy a year.
Though weeds aren’t a new issue – Shakespeare frequently cited the unmitigated growth of weeds as a sign of governments’ impending fall – Cook said La Plata County made a belated entry to the war on weeds.
“We started out 40 or 50 years late with a weed-management program in the late 1980s, when weeds were already widespread in the county,” he said.
“Finally, people got serious and set up the Undesirable Weed and Rodent Committee, with funding for a full-time staff position. They hired me on July 20, 1992,” he said.
Since then, Cook has roamed the state, watching as new invasive species descend on Colorado and has equipped local farmers and ranchers with numerous means of fighting back.
The language of weed management heavily borrows from both the military tradition and epidemiology, for good reason.
Weeds fall into one of three threat categories. A, the highest-threat category, speaks to emerging weed species, which – if they aren’t contained early on – promise to explode, engulfing huge swathes of land and decimating regional ecosystems.
Weeds, like an invading army, wreak massive damage on entire ecological habitats and agriculture – sometimes to deadly effects. Cook said he’s frequently seen horses and occasionally humans fall down dead after ingesting water hemlock, mistaking it for a parsnip.
Much like spies in World War II or swine flu, weeds flourish in our great cities. It’s lore that the North American weed fleabane traveled to Europe inside a stuffed bird sometime in the 17th century in mere seed form. Now, it thrives in stones of the Bank of England.
Similarly, leafy spurge, a weed species native to the Netherlands and Germany, has successfully infested more than 3 million acres of the American West.
Cook recalled watching helplessly as the species took over one local 400-acre farm within just three years, rendering the land useless to its new owner as his cattle famished without grass.
Despite the grim realities of weed management, Cook enjoys the etymology of weeds’ names.
He said one of the weed species he’s most often called about, Scotch thistle, got its name by endearing itself to Scottish soldiers: When enemies attempted invasion, they’d take off their shoes in an attempt to be quiet. Then an invading soldier – often, English – would step barefoot on a thistle, yell his head off and alert the Scottish warriors to the unfolding raid.
Like many dominant weed species, leafy spurge is highly adapted: You can’t mow it away; it survives fires. And increasingly, herbicide – humans’ once lustrous weapon of last resort in the war on weeds – is a dulled blade. Like bacteria that have adapted to antibiotics, today, more than 217 weed species are resistant to at least one herbicide, according to the International Survey of Herbicide Resistant Weeds.
Cook said right now, one of his top concerns is oxeye daisy, “not only in the state or the county, but in the entire Rocky Mountain West.”
“Oxeye daisy is another insidious species that’s slowly converting our landscape to inedible land” that won’t support any life, he said.
You can even watch the oxeye daisy’s relentless approach on Google Earth, which shows it advancing on the slopes below Engineer Mountain.
Tenacious weeds don’t mind the elevation. He’s seen another invasive weed species, yellow toadflax, which is visually striking thanks to its “pretty little yellow snap dragon,” growing in Rocky Mountain National Park atop a tundra at 12,000 feet.
Of Colorado’s 3,000 native-plant species, about 500 have already been displaced by the spread of weeds.
Cook said Colorado isn’t yet Montana, but it’s getting there.
“Monocultures like that, we call them a biological desert,” he said. “When I drive through parts of Montana, where weeds have displaced native species, elk herds and predators, no animals live there any longer. I don’t even see roadkill,” he said.
cmcallister@durangoherald.com
For more information
For more information about La Plata County’s weed management program, visit laplataweeds.org, call 382-6470 or email county weed manager Rod Cook at rod.cook@co.laplata.co.us.
The county can survey properties and create a weed-management plans for landowners.
