Knowledgebase
What type of "grass" is this and how to control it? #864550
Asked April 15, 2024, 8:20 AM EDT
Carroll County Maryland
Expert Response
Hi,
Grass ID is difficult to narrow down and it helps to sometimes see seed heads, the ligules and the hairs along the stalks.
We can see what looks like the typical large ligules of Roughstalk Bluegrass of Poa trivialis in these photos and the purple stem is another tell tale trait. It rarely produces seed heads since it can mix in with regular grass seed mix and is mown at the same rate so pre-emergent herbicides like barricade are not effective.
It is difficult to get rid of and if you have a large population we recommend either treating it with a non-selective herbicide which would also kill surrounding grass and overseeding, or aerating and overseeding in the fall with a high quality grass seed mix which hopefully wouldn't contain any roughstalk seeds. Eventually the desired grass seed mix would overtime out compete the weed species.
Alternatively you could cut strips of it out and replace with strips of sod.
The first link will give you further guidance. Let us know if you have further questions.
Emily