How to Control Oxalis

Oxalis – Weed Control – Creeping Oxalis and Yellow Oxalis

Oxalis weed control and weed killer for creeping oxalis in lawns and other oxalis weeds. Most oxalis species are regarded as weeds. Weed control of oxalis is a common problem. Creeping oxalis in lawns and the common yellow flowering oxalis or ‘sour sob’ are perhaps the worst.

Removal or eradication of oxalis is not easy, however with persistence the presence of oxalis can be at least reduced. Systemic weed killers based on glyphosate can be used on oxalis, however they are not usually selective, and will kill everything they contact.

Oxalis and Creeping Oxalis removal or eradication

The small bulblets that oxalis produces are the problem, they are not easily removed by weeding and therefore the problem persists. Oxalis and Creeping Oxalis are difficult to control, we present a number of options.

How to Control Oxalis

We have found three methods, so here are our tips on how to control Oxalis and eventually kill it off.

• • Weeding.

    Constant and vigilant weeding can greatly reduce the presence of oxalis in the garden. If you do not let the plant flower and continually weed you will eventually reduce the problem. However with Oxalis weeding is very difficult as the tiny bulblets drop off very easily and weeding can actually spread oxalis if you are not careful

• • Weed killer for Oxalis.

    Using a weed killer will eventually do the job if you like using weed killers. However it will still take a few years to completely eradicate the problem.

    A glyphosate herbicide was seen as the best way to tackle Oxalis. Care must be taken when applying weed killers near shrubs and trees. We have had it reported that Bindi and Clover weed killer does give success . We are reluctant to use glyphosate herbicide because of reported health risks.

    So today we look for an organic alternative and that seems to be SLASHER. For us this works when applied in this manner.

    1. Spray with Slasher as soon as the Oxalis appears.
    2. As soon as the Oxalis reappears, spray again.
    3. Continue with this process through the growing season.
    4. NEVER let oxalis flower

    This process starves the bulbs if repeated each year, and you can eventually eradicate it.

  • Smothering.

    If you can prevent light from getting to the plant by smothering with a thick layer of newspaper covered with mulch the bulblets will eventually die. It can still take a number of years.

• • Organic solution.

    Many people believe in the use of vinegar solutions as weed killers, vinegar will kill foliage, but it will not kill the bulblets under the ground. Repeated applications are needed to eventually ‘starve’ the oxalis. Soap mixed with the solution will help penetration of waxy surfaces on some plants.

    Other methods

    A few ‘Household remedies’ and general tips include

    • Fly spray,
    • Sulphate of iron, also good for moss,
    • Get some chooks, they will eat it and dig up the bulbs as well
    • Keep at it for a number of years
    • Shade, matt it out with black plastic
    • Remove soil
    • Best time to treat is why it is active growth

• Are All Oxalis Weeds ?

  Of the dozens of species around 5 are weeds, many of the others make great garden plants, however the other 5 give all oxalis a bad name, sometimes not warranted.

Types of oxalis

• Creeping Oxalis, Oxalis corniculata is an invasive weed that will take over large areas in lawns, the roots creep beneath lawns, again difficult to control by weeding as the roots (tubers) break easily.
• Oxalis pes-caprae also known as ‘Soursob’ produces a main root along with small bulbs this makes it difficult to remove by weeding as the bulbs tend to drop off fairly easily
• Oxalis corymbosa this is the pink flowering oxalis, again its the small bullets that make eradication difficult.

  We find that a glyphosate herbicide is the best way to eventually remove Oxalis. We have not yet found a selective weed killer for oxalis.