Barnyard grass elimination

Asked April 19, 2017, 10:51 PM EDT

i want to eliminate barnyard grass from my lawn. Both the front and back yard are overgrown. The house was built in1979 and the previous owner did not bother to get rid of it when it started growing. I tried various chemical treatments including Roundup for Grass, but no luck. Rob Proctor identified it last year.

Denver County Colorado lawns and turf

3 Responses

Barmyardgrass is an annual grass that would be germinating from seed about now, so it would be very small, not yet prominently visible in your lawn. By midsummer, it will show its typical flattened stem, often reddish at or near ground line (photo). It has very distinctive seedheads. It is also known as water grass because it thrives in moist soils that may not drain well.

So, if you are seeing a well-established, large grass that is now green and actively growing, it's not barnyardgrass. If I had to guess, it would be that you have some clumps of tall fescue (a perennial grass) in your lawn.

Barnyardgrass is best eliminated by keeping it from maturing seedheads.

Pre-emergent herbicide ("crabgrass preventer") applied in late March will keep barnyardgrass from appearing in your lawn.

Another weedy grass possibility is that you may have quackgrass, an invasive, fast-growing Noxious Weed in CO.

Quackgrass spreads quickly from underground rhizomes. It appears early and greens up quickly, before the desirable Kentucky bluegrass of your lawn does.

Right now it would appear taller and wider-bladed than the Kentucky bluegrass it is growing in. It has a blue-green-greyish color

If you're still interested in trying to eliminate this grass from your lawn, I'll need a few photos and description.