Early-Season Treatment of Fig Buttercup (Ranunculus ficaria)

Abstract

Fig buttercup is a perennial herb native to Europe, temperate Asia, and northern Africa. In eastern North America, fig buttercup competes with native spring ephemerals, complicating control techniques. If chemical control could be shifted earlier in the year, the potential to negatively impact spring ephemerals would be reduced. We tested glyphosate applications on fig buttercup in northern Virginia under three early phenological phases (preflowering, early flowering, and 50% flowering) to assess the effectiveness of early-season treatment. Treating when approximately half of the plants in the population were in flower resulted in a 95% decline in fig buttercup. Treating when the first flower in the population had emerged resulted in a 90% decline. No later phenological phases were treated. Control of fig buttercup led to an increase in cover of Japanese stiltgrass, an invasive grass.