For Alicia Doran, conversations in her office often get really deep into the weeds.

Literally.

Doran is the coordinator for Jefferson County’s Invasive Species Management program and a local expert on noxious weeds — plants that grow aggressively and pose a threat to agriculture, wildlife or property.

Noxious weeds are a big problem not only in Jefferson County but across the state and the county, where economic losses to invasive species can be devastating, Doran said.

In Colorado, a 2022 assessment conducted in Montezuma County tallied economic losses as a result of invasive plant species at more than $5 million.

The U.S. Department of Agriculture estimates that noxious weeds, spreading across more than 100 million acres, cost the North American economy an average annual cost of $150 billion.

Invasive weeds make their way into an area, primarily through human activity, Doran said, pointing to new construction, soil disturbance, and the planting of known invasive plants, whether intentional or unintentional.

Doran cited the myrtle spurge as a classic example.

Prior to its listing on the county’s official noxious weed list, the myrtle spurge, a low-growing perennial with fleshy, blue-green leaves, had been widely sold as a “drought-resistant” plant.

“And it really likes this area,” Doran said. “But it’s escaped and now it’s throughout the foothills and some very, very rugged, areas. Animals won’t feed on it. And so it’s just taking up space.”

Doran said one of the most effective means of controlling invasive weeds is to learn to identify them and then properly remove and dispose of them.

Another method is learning to prevent the spread.

With warmer weather, Jefferson County sees an increase in visitors recreating on county-owned and neighboring land.

Simple things — such as cleaning gear before and after hiking and checking clothing and for seeds and plant fragments — can make a difference.

This year, Doran said the county has designated the following as its Top 6 offenders: myrtle spurge, hairy willowherb, musk thistle, diffuse knapweed, leafy spurge, and orange hawkweed.

To promote awareness about invasive species, the county is hosting a “Purge Your Spurge” event, where residents can safely dispose of myrtle spurge.

The community event will be held from 8 a.m. to 2 p.m. on June 8 at the Jefferson County Fairgrounds at 15200 W. 6th Avenue in Golden.

Plants must be bagged before drop-off, the county said.

To learn more about invasive plant species in Jefferson County or to get help identifying a potential noxious weed, visit www.jeffco.us/795/Invasive-Species-Management.