Creeping Oxalis and why you may not have been able to kill it

Written by Ian Thompson

Ian holds a Masters in Turf Management from Sydney University, has over 20 years experience working as a golf course Superintendent, turf manager, product formulation and development. We call him our resident Lawn genius.

What exactly is a weed? Well, it’s basically a plant that’s growing where we don’t want it and while Creeping oxalis isn’t exactly the fastest grower and it doesn’t have spikes that ruin your backyard cricket game like bindii but it is something that has been slowly spreading around Australia due to it being quite difficult to kill. Here we cover how what it is, how to identify it and the best way to treat it.


What is creeping oxalis?


Creeping oxalis is a broadleaf weed it is found in unfortunately becoming increasingly common in home lawns. It is a heart shaped trifoliata that grows from a bulb below the surface however it propagates and spreads via stolons, hence the term creeping. There are lots of different types of Oxalis spp. and some of them are even used as ornamental plants, however the creeping oxalis (Oxalis corniculata) is not something you want in your lawn.


How to properly identify creeping oxalis


Identifying creeping oxalis from other broadleaf weeds is simple. The trick is to know where to look, in this case it’s a closeup examination of the leaves that will give away the identification. Just watch out, it is commonly confused with Clover and it’s often shown as a four leaf Clover on Saint Patrick’s Day which doesn’t help matters. Creeping oxalis is a heart shaped trifoliate. What that means is there are three leaves to each stem and each leaf is heart shaped. This is what distinguishes it from other trifoliate weeds such as Clover and medics.


Why is this a new weed?

Creeping oxalis isn’t exactly a new weed but if you go back 30 years it wasn’t anywhere near as common in home lawns as it is today. It’s a very slow spreader so its not this factor that has allowed it to spread, the reason its been able to spread is poor control results, that is people have been unable to control it eefectively. Don’t worry here at The Lawn Shed we have the answers to creeping oxalis.


How to properly kill creeping oxalis

There are a number of factors to ensure you get the best results when spraying for creeping oxalis, these include:

  • The right product selection
  • The use of a surfactant
  • Repeat application


Product selection

Many broadleaf herbicides on the market are systemic but some are better than others at this. For control of creeping oxalis we recommend Bow & Arrow, that’s because the chemistry in this herbicide has been proven to work and work well on creeping oxalis. It contains 3 active ingredients that have synergistic effects on weeds.


Use of a surfactant

Creeping oxalis has very small leaves and a high tolerance for herbicides so it’s important when applicating that we apply the herbicide in a manner that ensures the spray droplets don’t miss or simply roll off these tiny lives. A surfactant like Wetout breaks down the surface tension of the spray droplet, allowing the droplet to hit the surface and spread, meaning it more thoroughly coats the surface of the weed. This ensures the creeping oxalis absorbs more herbicide and that means better results.

Repeat application

Unfortunately, creeping oxalis is a very persistent weed. It has secondary survival mechanisms where sensing it’s in trouble from herbicide application, it can isolate the top part of the weed and then reshoot later from bulbs. So, a proper plan to knockout creeping oxalis will likely include a follow up application. This is best done as soon as the creeping oxalis starts to put on new growth. For small areas a second application should be sufficient however larger areas may require three or more.



The great news is they can both be killed by Bow & Arrow which can be found in the weed control area of our site.



The best way to spray for Creeping Oxalis

The best way to kill these trifoliate weeds is by adding 50ml of Bow & Arrow to 5L of water, also add 5ml of Wetout and apply evenly over a 100 square metre area.

Wetout is a high quality surfactant used at extremely low rates that reduces the surface tension of the spray allowing droplets to hit the small leaves of these weeds, instead of rolling off it sticks and spreads across the leaf. That means more herbicide is absorbed and better results.


Remember to make sure you read the label before making any applications. Ensure the lawn is not mown 2 days prior and 2 days after application. Keep pets and children off the lawn until the spray area has dried.


One last piece of advice for spraying liquids in general, make sure you use a high quality professional sprayer. We recommended a battery-operated sprayer as these maintain consistent pressure in flow, creating an even application of product whether it be liquid fertiliser, herbicide or insecticide.



If you’re looking for fantastic advice on any aspect of lawn care then you should follow along on our YouTube channel, LawnFlix where our resident Lawn Genius shows you how to apply, how to calculate and just generally everything lawn related.


Thanks for reading this blog, if you have any questions feel free to reach out to us. Don’t forget to subscribe to our newsletter below for well-timed lawn advice, because timing is very important in getting the best results for your lawn.

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