I have attached a photo of a weed that I cannot seem to control. I have used weed killers I got at the big box store that worked only temporarily. Other than applying Roundup or something similar, what can I use to get rid of this plant in my lawn? Thank you.
This is stiltgrass, a foreign invasive weed that is highly aggressive. In is best controlled in the lawn the crabgrass preemergent products. Here is our page explaining its habits and how to handle it: https://extension.umd.edu/hgic/problems/japanese-stiltgrass
Do not let is go to seed, as much as possible. Keep it pulled in beds. When you mow, direct the clippings onto the lawn so it won't get into beds or, especially, natural areas. It is very destructive in parks and wild areas.