SHERIDAN — Sheridan County’s efforts to combat the spread of invasive weeds will receive a significant boost from the Wyoming Legislature’s decision to allocate additional funding for weed and pest management this year, but sustaining those efforts may require an ongoing commitment from the state.

Sheridan County Weed and Pest Supervisor Luke Sander said Sheridan County’s environment has more moisture than many of the other counties in the state, which makes for a longer growing season that gives invasive species more time to take root.

Sander said the county has historically had one of the most severe leafy spurge infestations in the state but in recent years, two new invasive weeds — ventenata and medusahead — have emerged locally, which could spread to other parts of the state if they are not managed properly.

“We’re the epicenter, basically, of these new grasses,” Sander said. “So we’re really trying to keep them contained and keep them from spreading to the rest of the state.”

Sander said the invasive grasses are the first plants to begin growing in the spring and absorb water and nutrients that would perennial native grasses would otherwise utilize. 

Andrew Cassiday, the district conservationist with the Sheridan Natural Resources Conservation District, said ventenata and medusahead have a much higher silica content than the grasses native to Sheridan County, which means they are unpalatable and provide very little nutritional value to local wildlife and livestock. 

The weeds’ high silica content also makes them more flammable, which increases wildfire risk and frequency on lands where they are allowed to proliferate, Cassiday said. 

The emergence with those new species coincided with a sharp economic downturn in the state, which led to large cuts to funding available to weed and pest districts; Sander said Sheridan County’s annual state funding dropped from about $20,000 to about $6,000 in 2016. With that loss of funding, the spread of local invasive weeds accelerated.

“That really crippled our leafy spurge program and it was pretty tough on a lot of the land owners because the state lands that bordered them were the ones that they leased, and the state didn’t have money to control the weeds on them,” Sander said. “And a lot of that spread on their private lands.”

The Wyoming Legislature’s appropriation during its latest session — which will provide the Office of State Lands and Investments with an additional $500,000 to distribute among the 23 weed and pest districts throughout the state — is an effort to restore the funding that was cut previously.

Though the Office of State Lands has not determined how much money each county will receive, Sander said he plans to request between $50,000 and $60,000 of the new funding, which will help his department work with the Northeast Wyoming Invasive Grass Working Group, a coalition of regional groups and private land owners that have partnered to manage invasive weeds, control the spread of ventenata and medusahead over the coming year.

The funding increase is only for the year, however, and effectively stopping the spread of invasive weeds will take several years, Sander said. He said his group treats Sheridan County lands with a chemical called Esplanade, which is effective but relatively expensive.

Cassiday explained that the treatment is designed to prevent invasive seeds from taking root. 

“The primary means of herbicide control for them is to suppress the germination or establishment of those seeds in order to deplete the seed bank,” Cassiday said. “If we can deplete the seed bank of those species on a given site, we can eliminate it, or at least substantially reduce it.” 

Depleting ventenata and medusahead seed banks at local sites, though, would require several treatments over several years, Cassiday said. 

“Sustaining (treatments) over time really is the key to getting a long term handle on these species, or any invasive species,” Cassiday said. 

Sander said if Sheridan Weed and Pest could apply two or three Esplanade to local treatments over the next 10 years, it could deplete the seed bank of ventenata and medusahead.

Managing invasive species in Sheridan County could prove to be important to many other areas of the state as well.

“There’s a huge risk of these grasses spreading far enough into the sage grouse areas, which would be pretty detrimental to the sage grouse that we’re trying to protect in Wyoming,” Sander said.

Consistent funding would also help weed and pest districts eliminate invasive weeds before they cause infestations.

“If we could have controlled leafy spurge, got to it before it got to be a problem, we could have saved millions and millions of dollars,” Sander said.

Sander said he and members of other weed and pest districts in the state plan to continue lobbying the Wyoming Legislature to make the funding increase for weed and pest management ongoing.

In a recent column published in The Sheridan Press, Sen. Dave Kinskey, R-Sheridan, said he also planned to work for a more consistent increase to weed and pest funding.