Preemergent control of Nimblewill (Muhlenbergia schreberi)
Marian, thank you for your response. I have a follow-up question. You stated there is "no preemergent that will effectively control this grass as it is a perennial not an annual grass". Because it is a perennial, nimblewill will regenerate from the rootstock. From what I read elsewhere Nimblewill does produce seeds in late summer. I am trying to understand why a preemergent control would not keep nimblewill seeds from germinating. I plan to mechanically and or use Roundup to kill the active nimblewill grass but I am concerned that the seeds will germinate in the spring. Will a preemergent such as Dimension, Barricade or Scotts Halts at least keep the new nimblewill seeds from germinating? thanks again,
Perennial grass weeds are not controlled by preemergent herbides. The herbicides you mentioned above would not be effective. Nimblewill can spread by stolons and seed. If the nimblewill is mown a regular basis, it may not go to seed. Otherwise, if seed is present, you can bag the grass clippings.
Post emergents and nonselective herbicdes are used for nimblewill, a perennial grassy weed. Here is more on lawn herbicides, perennial grassy weeds, and a link from Penn State
Preemergents are used for annual grassy weeds such as crabgrass and stiltgrass.