Vulpia Control

In November 2021, Nate Johnson, then with Ecostudies Institute, asked the Listserv for input on using clethodim to treat Vulpia species (i.e., effective application rates and timing). His Fusilade DX treatments had been unsuccessful in controlling Vulpia, and he was looking to re-evaluate other grass-specific herbicides.

Elaine Stewart from Metro responded that she’d had success using a mix of 1% clethodim, 1% sethoxydim, and 1% Competitor in the fall and noticed improvements in native annual and perennial forb cover in the treatment area. Wes Messinger of USACE asked about the response of Festuca roemeri to clethodim, as clethodim is also used for control of fescue species. Elaine noted that nearly all the Roemer’s fescue in her treatment area had likely been killed by clethodim. Linda Boyer of Heritage Seedlings echoed Elaine’s suggestion that F. roemeri does not tolerate clethodim and added that it does seem to tolerate fluazifop. Nate Johnson expressed concern about using clethodim at 1% concentration on sites where fescue grows. Peter Moore with the Institute for Applied Ecology responded that F. roemeri was unaffected by clethodim and sethoxydim when he’d sown it in the fall and sprayed the following spring. Dave Wilderman of WDNR added that he had not observed any damage to Roemer’s fescue from clethodim when using 0.67-0.75% concentration in spring and fall applications.

Clethodim seems an effective option for controlling Vulpia species, but avoiding damage to native grasses may require experimentation with timing and application rates.