Invasive patches of light green grass in my lawn.

Asked May 1, 2019, 5:21 PM EDT

I have patches of light green grass in my lawn that I feel is invasive. There are two different types of grass patches. One patch has a straw-like tubular stem which grows twice as fast as my normal lawn. The other is a finer light green grass with a head of seeds on it. I know what crab grass is and these patches are not crab grass. I would like to know what type of (weed) grass this is and what can I do to kill it? Thank you. Jim Andresen. Middletown,MD

Frederick County Maryland lawns and turf plant identification

3 Responses

Would you be able to send us photos of the plants in question so we can take a look? We have photos of the most common lawn weeds on our website -- as well as management information. Take a look and see if you find the ones that match what you are seeing. https://extension.umd.edu/hgic/topics/lawn-weed-id-and-management

If you are not sure, we would be happy to look at photos of the plants and determine what they are. Click on "choose file" below and then you can upload up to three files from your image library.

Christa

Thanks for your response. Looking at your pictures on the website I definitely have annual bluegrass and rough stalk bluegrass(poa trivialis). How do I get rid of these invasive grasses? There is a lot of rough stalk bluegrass along my property line and my neighbor’s. It is gradually spreading into my lawn.

Poa trivialis is a perennial grass, which spreads by stolons and seeds. It is challenging to deal with since it cannot be effectively controlled by any selective herbicides currently on the market. It seeds once a year which is happening now. Later in the season, it blends in with fescue grass.

The best way to manage Poa trivialis is to use a systemic herbicide, namely one containing the ingredient glyphosate. Glyphosate can be found in many products, but originally only in Round-Up. This will leave dead patches that will have to be reseeded. Total control of this weed is very doubtful. Please see the following information from our website, http://extension.umd.edu/hgic/topics/roughstalk-bluegrass.

Annual bluegrass can be controlled with a pre-emergent herbicide applied in mid-August/early September before the seeds germinate. See our website for more options. https://extension.umd.edu/hgic/topics/annual-bluegrass

A healthy, dense, vigorous lawn is the best defense against weeds. Practices that contribute to fewer weed problems include:

https://extension.umd.edu/hgic/topics/conditions-favoring-lawn-weed-growth

Christa