invasive lawn weed

Asked March 21, 2016, 6:26 PM EDT


The leafy weed in the attached pictures is starting to take over our lawn and has even come up in some planting bed areas. I was wondering what it is and what is the best way for a DIYer to get rid of it in terms of a specific herbicide that does not take out the grass?

Thank you, Tom

Denver County Colorado

2 Responses

Those are wild violets (Viola spp.). They can be difficult to control because they have deep underground roots. When hand-pulled, the top of the plant breaks off leaving behind enough of the underground roots to allow the plant to regenerate. New plants start from seed, too, so pick the flowers before they go to seed.

Often violets will grow in shady spots where the grass has thinned out or the soil is compacted. Your first line of defense may be to improve the condition of your lawn. If it's compacted, get it aerated this spring, and, if necessary, reduce the shade in the area to allow in more sunlight.

If you apply an herbicide for control, use a product labeled for broad-leaf weed control. It selectively will kill the weed but not the grass. Look for a product containing the active ingredients 2,4-D, MCPP, dicamba or triclopyr. Be sure to read the label to make sure it is safe for your type of grass - presumably Kentucky Bluegrass? - and follow all labeled application instructions and safety precautions.

Hi, Thank you very much for your helpful reply. I think the shade aspect of this weed spreading is absolutely correct as it seems to have started and flourished on the side of the yard that is shaded by the property line fence and my neighbor's big tree and house. It could be best to convert that area next to the fence to a planting bed after the weed is killed off. Between snows I've started picking the flowers off to prevent the reseeding but it seems like only the newest plants are flowering because there are no flowers on much of it. With warmer temps forecast for next week I hope to get the sprayed and aerated soon. Thanks again for your help!