Oxalis, which is also known as shamrock, is a frustrating weed that can make any avid gardener want to tear their hair out while screaming death to oxalis! As soon as you learn how to kill oxalis and think you’ve managed it, it’s back again! Can you ever get rid of this crawling, creeping oxalis weed? 

The more you know, the more likely you are to be in the driver’s seat and take control. Here’s everything you weed, er, need to know about oxalis in NZ – which includes what it takes to say goodbye to it for good!

What is Oxalis?

Oxalis goes by many names. Some people call it shamrocks because of its clover-like appearance, but it also goes by wood sorrels or its Latin name Oxalis Acetosella. For some unknown reason, the name “Good Luck Plant” is thrown around as well. Other standard terms, at least in the gardening world, are “please stop growing back” and “why won’t you die!”

Oxalis is a rhizomatous flowering plant with trifoliate leaves. In summer and spring, small white and pink flowers may appear which can make it quite pretty to look at. Don’t let its beauty fool you, for this plant will show its true colours before long.

Is Oxalis Toxic?

In a word – yes. Oxalis is toxic, but it’s not clear-cut. The Shamrock Plant is listed on the ASPCA’s website as toxic to dogs, cats, and horses. It contains soluble calcium oxalates, which can cause tremors, salivation, and kidney failure. The toxicity relates to all parts of the plant. If you own curious pets, you’ll need to be in a hurry to remove this plant permanently.

The oxalis weed can also be toxic to humans, but only in large quantities. You can gather the leaves and stems for salads or cups of tea because they have a lemon-like flavour which can be thirst-quenching. As they contain oxalic acid that binds up your body’s calcium supply, you should never consume oxalis in large doses. If you do, you are at risk of illness with staggering, cramping, and trembling, among many other symptoms.

How Do You Treat Oxalis?

There is a multitude of different approaches you can take to eradicate this plant. From killing oxalis with baking soda, through to putting your roaming chickens on the case; there’s quite the list of things to try. Not all solutions will work for everyone.

Many people used to use glyphosate-based weedkiller because it would travel down the stems and take care of the roots and bulbs. But glyphosate doesn’t discriminate, so it can also be harmful to bees and not safe for use around edible plants.

If you have oxalis around your succulents or perennials, you can give Death to Oxalis a try. This product burns oxalis leaves, which then weaken the plant and eventually starve it. It doesn’t work on creeping oxalis, however.

Boiling water can work a treat, but can harm your other plants, and black polythene can stunt growth but impact your soil health in the process. It seems that for every solution, there’s a drawback.

If you have a lot of time on your hand (and by time, we mean years), you can remove every single leaf by hand. Shamrock, or oxalis, can’t make food from the sun’s energy (photosynthesis), so if you remove its leaves, it will starve. Alternatively, let your chickens on the loose to clean it up in no time.

Baking soda is another wonderful product with many uses. Mix one tablespoon with one litre of warm water and a single millilitre of Rainguard and spray the leaves to burn them on a hot, sunny day.

Finally, the only other option is to live with it. If you try to attack oxalis like any other weed, it will multiply. Let it sit and act as ground cover and focus on the other, less invasive plants in your garden. You can also get in touch with lawn care experts who may have some other cheeky solutions up their sleeves.

What Are Some Uses for Oxalis – and Is It Edible?  

Oxalis is a pesky plant that’s challenging to remove, but at least it’s not entirely useless. It actually has a few different uses. The dried or fresh leaves are often used for medicinal purposes, such as for boils or abscesses.

Because oxalis weed leaves contain oxalic acid, they have a tangy bite to them. Therefore, they work well (in small quantities) in tea, salads, soup, and sauces. The flower, when left raw, is a lovely decoration in a salad. If you dry oxalis, it becomes useful as a curdling agent in plant milk. Save the juice for the removal of iron mould stains in linen.

Conclusion

Oxalis can be your worst nightmare, but only if you don’t know how to remove it, treat it, and use it. Take note of these helpful tips for removal above, and consider whether you may be able to use the plants once you remove them. There’s more to this pesky plant than meets the eye.