In April 2015, Ian Silvernail (Institute for Applied Ecology) emailed the listserv for guidance on managing Ranunculus repens (creeping buttercup) in an area with some established natives. He was particularly interested in a broadleaf specific herbicide that would be effective, and noted that 2,4-D and a mixture of tryclopyr and clopyralid were ineffective.
Richard Hebda suggested spot-applied Roundup on young plants, before the production of runners, and weeding recalcitrant root crowns. Tremaine Arkley found that digging them out early in the season was very inexpensive and effective. Dave Miller suggested a 2-5” mulch layer over the plants to weaken them. Louise Goulet had success with cutting the roots off about .5-1” underground. Roderick Gilbert suggested spraying with glyphosate and ammonium sulphate in the winter, when fescue may be hard to kill, or spraying triclopyr earlier in the season. Marty Chaney provided a link to the PNW Extension Weed Management Handbook and suggested adding a surfactant.