Control Annual Bluegrass Vs Rough Bluegrass
Q: What is the difference between annual bluegrass and rough bluegrass?
A: Annual bluegrass, Poa annua, is a very common grassy weed in local
lawns. It is a lighter green than fescue and really stands out against the brown
of dormant bermuda grass. Clumps are usually covered with hundreds of
Rough bluegrass, Poa trivialis, is a perennial weed.
Both grasses fade away in May, leaving dead spots in your lawn, but rough bluegrass returns in September. Annual bluegrass can be controlled with pre-emergent herbicide applied in September but controlling rough bluegrass is limited to two methods: dig up the clump or spray it with glyphosate (Roundup, etc).
Replanting your desired grass is necessary with whichever control you choose.
ID and Control of Annual Bluegrass and Rough Bluegrass in Lawns