We think that we may have creeping woodsorrel (​Oxalis corniculata​) taking over our front lawn. It is clover-like and has yellow flowers.
Is there any way to eradicate this?

Thank you.

Sincerely,

Tammy Falcone and Paul Aiken

Hi there Tammy and Paul,

Thank you for reaching out to us! 

It looks like you may have Yellow Woodsorrel (Oxalis stricta) rather than Creeping Woodsorrel (Oxalis corniculata).  The Creeping Woodsorrel tends to be more purplish in color than the plant in your photos.

It can be a tough weed to get rid of.  It spreads by both seed and rhizomes.  It is a perennial weed, so the plants you have now will come back next year. While we always say to not let your weeds go to seed and to physically remove them or cut them back before they go to seed after flowering, this isn't always an effective way to manage a weed like this in your turfgrass. Both pre-emergent and post-emergent herbicides would effectively control this weed when applied properly. Pre-emergent herbicide applied in Spring will keep the seeds from germinating into new plants and selective post-emergent broadleaf herbicides will kill the existing weeds.  It would be most effective to spray them in the fall, as this is when the plant will be actively sending its energy reserves down to the roots for winter before it goes dormant, so the herbicide will translocate to the roots quicker to kill  them. Remember that with any chemical you must read the entire label and follow all directions and to make sure that any herbicides used are OK to use on your grass (so it won't kill your grass too).

Here are links to more information about this plant and methods of control:​

https://extension.psu.edu/lawn-and-turfgrass-weeds-yellow-woodsorrel-oxalis-stricta-l

https://extension.wvu.edu/lawn-gardening-pests/weeds/yellow-woodsorrel

This is a great publication from the University of Nebraska about broadleaf weed control in lawns:

https://extension.unl.edu/statewide/ckb/Broadleaf%20weed%20control%20in%20home%20lawns.pdf

Hope this helps! 

Thank you,

Dawn

Master Gardener Coordinator, Arapahoe County CSU Extension

You're welcome!

Dawn