Knowledgebase
How to kill dandelions but not clover #867602
Asked May 08, 2024, 2:36 PM EDT
We're in Monument, CO at 7400 ft. We planted a variety of grass seed last fall, primarily a variety of fescues, a small amt of blue grass and about 10%+ white clover.
It was late fall so we didn't kill weeds before trying to get some seed to grow before winter snows. We have basically crabgrass, dandelions and in the 1/4 acre planted on this 1 acre lot, some good growth has started of the seed planted.
We would like to eradicate the dandelions without killing off the clover newly growing. None has been mowed yet. We even had a light freeze last night.
We are digging them out in spots, but a lot. We will carefully spot as many as possible with vinegar, salt and soap mix soon.
The goal is not to have a blue grass lawn. Not the neighborhood. Would like to plant lots of wildflowers since we only have to mow twice per yr per HOA rules.,
Is there a selective weed killer that we can apply to the entire acre to prevent the dandelions from going to seed and not killing the newly planted clover?
Suggestions?
El Paso County Colorado
Expert Response
Thank you for contacting Ask Extension. You would like to control the dandelions in your new lawn without harming the clover. Unfortunately, chemicals that can kill broadleaf plants and not the lawn can kill both dandelions and clover. I am sending a fact sheet about Broadleaf Weed Control in Lawns. Dandelion control is discussed.
https://cmg.extension.colostate.edu/Gardennotes/552.pdf
"The best time to apply a general-purpose broadleaf herbicide for the control of perennial broadleaf weeds such as dandelion, plantain, and clover is early September to early November. As winter approaches, perennial broadleaf weeds are storing energy reserves in stems and roots; a fall-applied herbicide will enter
the plant and travel to these plant parts with the food reserves. The second best time is in the late spring or early summer period after the weeds have flowered. If applying in the late spring, be extremely cautious with these herbicides near ornamentals, trees, flowers, and vegetable gardens because these plants can be damaged by these herbicides through direct application, drift, and/or volatilization (the herbicide turns into a vapor). This is another reason why we prefer to apply these herbicides in the fall."
If you decide to spot spray or paint the dandelions with the recommended herbicide please be very careful to keep the chemical from coming into contact with desirable plants. Digging up individual unwanted weeds remains an option.
You have mentioned applying a vinegar, salt and soap mix to the weed. A top kill application would kill the top of the dandelion but not the root. Salt can render the soil uninhabitable for many months, the soap can contain salts and vinegar may only kill the leaves. Horticulture vinegar, 20% acetic acid, can be very hazardous to handle, it could blind you.
https://cmg.extension.colostate.edu/wp-content/uploads/sites/59/2020/03/Natural-Herbicides-for-Landscape-Weed-Management-2018.pdf
You had mentioned planting wildflowers. I am sending information about how to plant a wildflower garden.
https://extension.colostate.edu/topic-areas/yard-garden/wildflowers-in-colorado-7-233/
Regards,
