One of the most despised broadleaf weeds in lawns is Oxalis corniculata (or Creeping Woodsorrel). This perennial weed creeps across lawns and forms roots and stems where it contacts the soil. It grows in sun or shade, moisture or dryness, poor soil or healthy soil. It’s virtually unstoppable.
The only debate about Oxalis is who hates it more, the property owner or the lawn care service attempting to get rid of it. In the world of weed control, this is one of the broadleaf weeds classified as a “difficult to control” weed. It doesn’t roll over and die like dandelions or clover. This weed is just plain tough.
What is Oxalis, A.K.A. Creeping Woodsorrel?
The leaves resemble clover, but are slightly different. Oxalis leaves are comprised of 3 heart-shaped leaflets attached to the tip of a long stem. Plants most often emerge light green but turn to burgundy when exposed to heat or stress.
The blooms are distinctive yellow flowers and show up almost any time during the year. As with most plants, after the blooms comes the fruit, A.K.A. seeds.
How Does Oxalis Spread in your Lawn?
One of the reasons you have a difficult time killing Oxalis in your lawn is because of the way it disperses its seeds. In one plant alone, there are 10-50 seedpods, meaning a potential for 5,000 seeds per plant.
When the seedpods mature, they burst, being shot up to 10 ft. away from the plant. They can also stick to mowers, clothing, shoes, and pets and drop off throughout the lawn. This is how Oxalis can become such a big problem in a short time in your lawn.
To make it even worse, Oxalis seedlings grow rapidly forming a taproot that is often snapped off during hand-pulling. Extreme hot or cold won’t kill Oxalis seedlings and they will reach their own reproductive capacity in 4-6 weeks. It is built for survival and to spread.
Mowing and Pulling Oxalis
So how do you kill Oxalis in your lawn? While you may be tempted to pull weeds in your lawn, sometimes that isn’t the best method. Oxalis taproots can be easily broken leaving root sections that will re-grow.
Pull a plant that is ready to expel its seeds and you’ll find that the seedpods burst in your hand. This causes those seeds to fall to the grass below. It’s not a complete waste of time to pull this weed, but it’s not the best method.
Mowing your lawn at 3″ year-round will also help your turfgrass to be healthier which can make it a little more difficult for Oxalis to grow.
Weed Control for Oxalis in your Lawn
When Oxalis does start growing in your lawn it is important to have a lawn care service spray post-emergent weed control throughout the year. One or two treatments may be enough to get decent control on dandelions and others but Oxalis takes repeated efforts, with 3-5 treatments from spring through fall.
Likewise, there are numerous types of post-emergent weed controls that claim on their label to control Oxalis. However, some are better than others, and some can only be purchased by a professional lawn care company to apply to your lawn. Throughout the year, we change our broadleaf weed control material to best manage certain weeds such as Oxalis.
We also add a surfactant (a sticker) that helps the liquid weed control material to evenly coat the leaves and stick without beading off. Our lawn care experts use a variety of spray equipment based on the size of the property. These machines are calibrated correctly to deliver fine droplets of weed control onto Oxalis and other weeds for even coverage and maximum control.
A Difficult, but not Impossible Weed to Control
As you can see there are recommendations to kill Oxalis in lawns, but it is still a very difficult to control weed. It could take years to get a level of weed control that you’re happy with but it is possible if you and one of the lawn care companies you may choose are diligent and attentive.
If you’d like to talk about how our lawn care service can help improve your lawn, we would love to meet with you at your property and provide you with a free lawn care consultation.