Bad grass in Kentucky Blue Grass lawn

Asked June 26, 2019, 1:39 PM EDT

Hello, Would anyone at the extension office be able to take a guess at this grassy weed that is contaminating my kentucky blue grass? Glen Burnie, MD 21061

Anne Arundel County Maryland lawns and turf weeds invasive japanese stiltgrass stiltgrass nimblewill plant care

3 Responses

It's difficult to distinguish the weedy grasses in your photos. They look freshly mown. Two possibilities are:
nimblewill. This is a perennial grass, somewhat grayish or blueish compared with Kentucky bluegrass. Here's how to manage that: https://extension.umd.edu/hgic/topics/nimblewill
Note that the photo shows both nimblewill (blueish) and Japanese stiltgrass.

The second grass you likely have is Japanese stiltgrass, simply known as stiltgrass. Here's that info: https://extension.umd.edu/hgic/topics/japanese-stiltgrass
This is an annual grass, and its management is completely different. If your weed grass disappears in the winter, it's probably stiltgrass.

Incidentally, a Kentucky bluegrass lawn is high unusual. Kentucky 31 is a variety of tall fescue which is often sold and which is a better grass suited to Maryland weather.. Kentucky bluegrass tends to die out rather quickly from disease and pests.

Ellen

Ellen,

Thank you, the yard is irrigated and contains a mix of Kentucky bluegrass and perennial ryegrass along with other blends of fescue.

Looking at the photo comparisons I think that you are absolutely correct in identifying nimblewill. Thank you for your help. Now I can take steps to control it.

-Adam