By Victor Shelton
This spring, I’ve received multiple inquiries about a yellow-flowered plant appearing in pastures and fields—seemingly more problematic than usual. That plant is buttercup (Ranunculus sp., not to be confused with Cressleaf Groundsel, Packera glabella; syn. Senecio glabellus), and while its bright yellow flowers might seem pretty to some, it’s definitely unwelcome in pastures and hay fields, especially if you’ve recently seeded hay fields or are trying to establish new forages.
Despite its seemingly sudden appearance, buttercup’s growth is due to a buildup of its seed bank, often accumulated over time. This buildup can happen through hay equipment contamination or, more commonly, from bringing in hay containing buttercup seeds and spreading manure from that hay. These seeds can lie dormant for years—typically 3 to 5, but sometimes longer—waiting for the right conditions. This is why buttercup seems to “suddenly” appear, even if it wasn’t noticeable in previous years.
Buttercup thrives when soil conditions are favorable, particularly after overgrazing or soil disturbance, which leaves bare spots where the seeds can establish without much competition. This spring’s wetter-than-usual conditions have exacerbated the problem, as buttercup flourishes in wet, compacted soils and bare ground—conditions that often follow overgrazing and limited pasture rest. The dry fall didn’t help either. If pastures are overgrazed or if livestock have had heavy foot traffic when the ground was soft, you’ve provided buttercup with the perfect environment to spread.
Competition is key to controlling buttercup. Healthy forage species must remain strong to outcompete it. If desirable plants are overgrazed or there’s bare ground, buttercup can take hold. Bare soil acts like a blank canvas for buttercup to grow quickly. The more competition from healthy, well-established forage, the less chance buttercup has to dominate.
Source : osu.edu