The announcement that glyphosate is a carcinogen has resulted in new ordinances in some southern California cities. The new ordinances being considered or adopted are limiting the use of products containing glyphosate on city-owned property. Alternative herbicides are needed.

Area IPM Advisor Cheryl Wilen tested herbicides—most of them organic or biopesticides—to see if they may be a suitable replacement for glyphosate for weed management. Wilen applied two treatments to test plots containing hairy fleabane, annual sowthistle, Jerusalem oak, and common purslane. “While I’m still evaluating the data, I can say that some products look pretty good. While the costs are high, at least the cities can narrow down what products would work for them,” says Wilen. Several of the products with potential for controlling weeds were organic, although Wilen noted that their signal words indicated they were more hazardous than glyphosate.

Wilen’s research improves knowledge of how well alternative herbicides to glyphosate manage weeds. It is anticipated that cities that use the tested alternative herbicides might save money by using the best herbicide for their situation and budget.