The annual nature of this weed supplies its most noxious habit: it re-seeds itself prolifically! Annual bluegrass is outwardly attractive in the winter but just wait until spring! The thick mat of bluegrass chokes out the better turf underneath.

Every blade (of which there are thousands) seems to be covered with seeds. These seed are carried by animals, water and lawnmowers to other parts of the lawn. When hot weather comes, the bluegrass dies, leaving a large bare spot and a legacy of thousands of seed for next fall.

The best control for annual bluegrass is to apply a pre-emergent weed chemical in the fall. The best time is usually in mid-September. Any pre-emergent product that controls crabgrass will control annual bluegrass.

The pre-emergent will prevent seeds from germinating. Of course, the pre-emergent could not be used on a fescue lawn which you intend to re-seed!

If bluegrass is present in bermudagrass in January, the best control is to kill it with a non-selective herbicide (Roundup etc.) before it forms seed in the spring. Read the label to make sure your desired turf grass will tolerate the chemicals in the winter. Make sure bermudagrass is truly dormant before spraying and spray lightly.

The old-timers call this one "po anner" due to its scientific name: Poa annua. That name immediately tells us that this grassy plant is an annual. It has appeared yearly in patches throughout my St. Augustine grass back yard. It is not killed by a broadleaf weed killer. Conversely, a grassy weed post-emergent herbicide might hurt my turfgrass.

This is where a non-selective herbicide can help - if it is properly applied. I can see that my St. Augustine has some green sprouts in winter, so I can't use a spray of Roundup(tm). Instead, I wrap an old towel around the tines of a yard rake and dampen it with the diluted chemical. Using the rake like a paintbrush, I apply chemical to the "bad" grass without harming my "good" grass.

pre-emergent