It may have seemed slightly nuts to clear brush in Cottage Grove Ravine Regional Park in the middle of February.

That's by design, says Andy Schilling, watershed resource specialist at the South Washington Watershed District.

The conservation group worked to clear 20 acres of invasive buckthorn and honeysuckle along a section of paved trail north of Ravine Lake and south of the pine plantation below the Washington County South Service Center.

They planned to finish by end of the month, Schilling said, but the work might extend into March.

Working in winter should inconvenience the fewest number of park users, he said. This time of year, that would consist mostly of cross-country skiers who use the usually snow-packed trail.

Schilling said they contact the Washington County Parks & Recreation Department 24 hours in advance of any work. The county posts the information on social media.

"We just wanted to make this project move through as quickly as possible so the park and remain open," he said. "The work does fall near the paved trail. We just want to limit the amount of time we're there."

Skiers and others who use the trail should be alert to the possibility of motorized equipment on both sides of the trail.

Another reason for working in the winter is that the frozen ground sustains less damage from the equipment.

Workers cut non-native plants and shrubs and mulch them on site. Most were treated with a herbicide to prevent them from regenerating.

"You disturb the soil much more when you're yanking them out by the roots," Schilling said. "It's also more expensive. This is kind of a best practices."

This work is part of the watershed district's Central Draw Overflow, a multiphase project that will help control stormwater runoff from Woodbury and Cottage Grove.

"By removing the invasive species like buckthorn we are allowing native groundcover to establish itself and, in effect, make the ground more resistant to erosion," Schilling said.

For additional information on the project, contact Schilling at the South Washington Watershed District at 651-788-5279 or Dan MacSwain with Washington County Parks and Recreation at 651-430-4323.