Discussion of herbicide control methods for velvet grass (Holcus lanatus) from the CPOP Listserv.
Summary
In September, Ian Silvernail with the Institute for Applied Ecology asked the Listserv for their successful control methods for velvet grass (Holcus lanatus). Silvernail’s attempts to control for velvet grass on a coastal prairie were successful in killing seedlings, but had no significant impact on mature plants. Several trials were conducted using different prescriptions of sethoxydim, clethodim, and methylated seed oil (MSO).
Rod Gilbert from Joint Base Lewis-McChord responded with his own recommendations on treating velvet grass. He suggested using Fusilade, but mentioned that timing is important: application should occur before the plants have developed culms and spikelets. Additionally, Gilbert mentioned that he used extra surfactant when treating grasses given their smaller surface area and that this was especially important when applying herbicide to velvet grass because the hairs on its leaves can cause the herbicide to sit on top of the plant. Dave Wilderman with Washington Department Natural Resources echoed Rod’s suggestion, adding that he has successfully treated velvet grass with Fusilade in the fall, after some rains and the plants were well green . Gilbert also has used Glyphosate successfully, but is only effective before a plant has finished flowering.