Weed identification

Asked June 14, 2020, 11:33 AM EDT

A weed which I've never seen before is invading my lawn (3 photos attached). Could you please help me identify it and recommend what I should do? In many places it is interspersed with the tall fescue grass and so is hard to eliminate manually. Would Weed-B-Gone work? Thank you.

Montgomery County Maryland

4 Responses

This looks like Japanese stiltgrass. This weed has become a large problem in lawns and natural areas. Weed-B-Gone would not control it. This spring a pesticide ban has gone into effect in Mongomery County. Organic herbicides can be used but their effectiveness is pretty limited. Please see the following information:

Montgomery County’s pesticide law bans the use of most synthetic pesticides, including herbicides, insecticides, and fungicides on private lawns, playgrounds, mulched recreation areas, and childcare facilities. Organic pesticides are allowed. There are some exemptions for the use of synthetic pesticides, including for biting insects, indoor pests, and tree and shrub pests. Go to the following website for information regarding the law and organic lawn care information, www.MontgomeryCountyMD.gov/lawns

You can also ask them questions, Email AskDep@MontgomeryCountyMD.gov or call 240-777-0311


Thank you very much for the reply. You know much more about this but, just to sure -- when I look at images of Japanese stiltgrass, the leaves seem more narrow than the leaves of my weed (when compared to the length of the leaves) , and it looks like Japanese stiltgrass grows quite tall whereas my weed seems to grow only within an inch of the ground. In any case, it sounds like the only approach is pulling it up by hand one plant at a time and trying to leave the tall fescue there? Or digging it all up with a shovel and replanting? Thank you again for your advice

This is an annual plant, so you are seeing young seedlings. (Plus, they look like they have been mowed in the one photo.)

Yes, these are Japanese stiltgrass. It has spread like wildfire through the mid-Atlantic. There is always some variation within a species and depending upon the environment.

Read the links carefully. You'll want to tackle it differently, depending upon where you're see it (beds, lawn, woodland, etc.j)

One approach is to let it grow a bit taller at the end of the summer, as it begins to form seeds. Then mow or pull just before the seeds mature, so it may not have enough time to produce more seeds.


Thank you!