A US court has blocked the resumption of open-air field trials involving genetically modified (GM) versions of creeping bentgrass and Kentucky Bluegrass. On March 17 the US Court of Appeals for the District of Columbia Circuit dismissed an appeal from Scotts Grass, of Marysville, Ohio, over testing the Roundup Ready grasses. The company appealed a 2007 ruling by a lower federal court, which found that officials of the US Department of Agriculture (USDA) had erred in approving plans for testing grass without first assessing environmental impacts. The GM grasses in field trials spread beyond the test fields to surrounding areas, including a protected 'National Grassland' area. Despite these findings, Scotts not only appealed the lower court ruling but also challenged the standing of one of the plaintiffs in that case, namely the Washington-based International Center for Technology Assessment (ICTA). “The court's ruling vindicates our challenge to USDA's inadequate review of these biotech grasses,” says Joseph Mendelson, who is legal director of the Center for Food Safety in Washington, DC, a sister organization to ICTA, which initiated several lawsuits against the company and USDA (Nat. Biotechnol. 25, 269, 2007).