Take a look at this unusual way to stop Annual Bluegrass, also known as Poa annua, this spring on Walter Reeves’ website. It is becoming one of the more difficult lawn weeds to control and this is a different approach to removing the weed if you have a little time on your hands. I should also point out that staying on a regular weed control program with regular pre-emergent applications throughout the year is the best defense against this weed. If you’ve missed this application, give this idea a shot and let us know how it works.
“Another way to control annual bluegrass in Bermuda grass is to wrap an old cotton towel around the end of a garden rake. Tie in place with string and dampen the towel with Roundup. Use the tool to “paint” weed killer onto green weed foliage while avoiding the turf grass. Discard the cloth when the job is finished by wrapping in plastic bags and putting it out for your municipal garbage collection.” Walter Reeves
Source: http://www.walterreeves.com/lawns/article.phtml?cat=27&id=98