The Santa Rosa City Council on Tuesday banned the use of synthetic weed-killers like Roundup at dozens of parks, buildings and medians around town.

The decision came on a unanimous vote — with Mayor Chris Coursey absent and barely any audience in the council chambers — to approve a one-year extension of the contract with a company that has provided city landscape maintenance services since 2014.

But it culminated a citizen campaign, initiated three years ago, to eliminate use of synthetic herbicides on city property.

The company, Golden Gate Landscape Management, has sprayed glyphosate-based weed killer on parks and other public property under its $509,000 annual contract. The council renewed the contract, but added a prohibition on glyphosate.

Officials told the council that use of products containing glyphosate had already been abandoned, and council members Jack Tibbetts and Julie Combs expressed thanks for their action.

“I think it’s fantastic,” said Anne Seeley, a Santa Rosa area resident and Sonoma County Conservation Action board member.

Weed killers like Roundup are “dangerous,” she said, and “inappropriate to be sprayed on areas where children play, where pets play.”

After the vote and council adjournment, Combs said she wanted to end the chemical’s use by all city departments, including Public Works.

Brandalyn Tramel, city purchasing agent, said the contractor had used glyphosate “sparingly and as a last resort” since 2014.

Tramel said she could not specify how much of the chemical had been used.

Scientific evaluations of glyphosate, first marketed by Monsanto in 1974 under the name Roundup, have varied widely over the years, with some studies associating its use with non-Hodgkin lymphoma.

Grassroots opposition to Roundup gained momentum last year when glyphosate was added to California’s Proposition 65 list of cancer- causing chemicals, over Monsanto’s objections.

Megan Kaun, a mother of two and former member of the city’s Board of Public Utilities, agreed that Tuesday’s quiet vote was anti-climactic.

But “it really is a big deal,” she said in a telephone interview, recalling some “difficult conversations” she had with city officials when she raised concerns about glyphosate in 2015. Kaun, now a Sebastopol resident and Conservation Action board member, objected to the city’s plan to spray Roundup on a playground at Hidden Valley Park near her former Santa Rosa home.

“I got this bee in my bonnet,” she said.

Officials said they would postpone the spraying if Kaun could get the weeds pulled by hand, so she enlisted neighbors and got it done.

Now, Kaun said, Conservation Action is pushing to “get toxics out of all public land in Sonoma County.”

The city will open its landscape maintenance contract to bidders in the next six to eight weeks. It expects to award a new contract by March.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.