Seeking to get a handle on this year’s larger-than-average grass crop, state firefighters on Tuesday staged a controlled burn of about 18 acres just east of the town of Glen Ellen.

The vegetation management effort started at 10 a.m. on the Bouverie Preserve, less than a mile from Highway 12, Cal Fire Capt. Jeff Hoag said. Firefighters used hand torches to set the blaze and stood watch until it was extinguished about five hours later, Hoag said.

“Heavy rains this year definitely gave the grasses a boost,” Hoag said. Crews were expected to remain on site into the night as a safety precaution. Overcast skies concealed much of the smoke.

Courtney Emer, manager of the nearby Mayo Family Winery, said she had no idea it was even happening.

“Honestly, I did not notice it,” Emer said. “If it was smoky, I must have mistaken it for fog.”

A Bouverie Preserve official said the burn had been planned since last fall. Sasha Berleman, a fire ecologist for Audubon Canyon Ranch, said the goal was to clear future fire hazards while improving the health of an ecosystem that has not seen fire since 1964.

“It has been much longer than the natural amount of time you would want to see go by,” Berleman said.

It’s one of several controlled burns scheduled in the North Bay this year before peak fire season arrives in mid-July. Another is planned for Sunday on the Pepperwood Preserve on Franz Valley Road. Others are planned for Lake Berryessa in Napa County in several weeks.

Record winter rains put an end to the drought, leaving high moisture levels that will alleviate some of the fire risk. But it also fueled vegetation growth that could become a problem this summer, Hoag said. The staged burns reduce the threat while providing firefighters with training opportunities, he said.

“We’re trying to burn away some of the grasses so they won’t burn later in the season,” Hoag said. “We get some training out of it, but the main purpose is vegetation management.”

You can reach Staff Writer Paul Payne at 707-568-5312 or paul.payne@pressdemocrat.com. On Twitter @ppayne.