Oxalis: Control and Prevention for Better Looking Gardens

There are over 900 species of Oxalis, a weed that is mostly considered a pest by many gardeners. Although some are considered valuable by horticulturists, certain species cause problems to gardeners. 

Most Common Oxalis in Australia

Oxalis pes-caprae L. also known as thumb, sour-sob, yellow sour grass, buttercup oxalis, Bermuda buttercup, and English weed. This is particularly common in the Southern area of Australia, New South Wales, southeastern Queensland, Victoria, and Tasmania. This was originally introduced to Australia as an ornamental plant, but today many see this weed as one to be eliminated, at the very least controlled.

Oxalis Corniculata produces small yellow followers soon followed by the emergence of upright seed capsules. It also has a variety with purple-leaved colours.

Oxalis Debilis produces deep pink flowers typically during the months from July through to September.

Oxalis Latifolia it produces deep pink flowers but appears during the months May through to September

Method of Reproduction:

Typically, Oxalis reproduces itself through the seeds it produces or the bulbs it forms. This makes it quite a challenge to get rid of once it has appeared in your garden, therefore, early detection and effort to remove this weed from your garden is the best defense against its spread.

Control of Growth and Spread of Oxalis

Depending on the type of oxalis infesting your garden, there are several methods you can perform to help eradicate and control its future growth:

Weeding

Although hard work this is the ideal solution if  your garden is not yet too dominated with this weed and if your garden is a manageable size and not too large. Do not let these weeds produce flowers.  Allow roots to fully dry in the sun and to  guarantee it wouldn’t simply grow back once it touches the earth, weeds should be carefully placed in bin or burnt.  This prevents seeds from germinating to other areas of your garden. It is quite a challenge in eradicating this weed because of it’s tiny bulblets may easily fall to the ground and germinate and the whole cycle starts over again. 

Smothering

The sun plays an important role for the growth and development of Oxalis. Smother the plant using a thick layer of newspaper and follow up with application of thick mulch if necessary to prevent them to continue photosynthesis. Without food to support it, it will eventually die off; however, it will take sometime before you completely eradicate it.

Organic Solution

Some gardeners recommend the application of vinegar solution to these plants. Rather than applying weed killers, the acidity level of vinegar is believed to help kill the foliage formed by these weeds. Nevertheless, repeated application of this solution together with soap will eventually starve these plants from nutrients and thus proceed to die off.

Weed Killer

At ePlants the best solution to this weed infestation is to apply glysophate [Roundup] at the recommended rate. Re-apply about 10 days later and then place fresh mulch over the area.[ See Smothering ] Apply care when applying this near the trees and shrubs so as not to produce unwanted side effects on your beloved plants. 

At ePants trade nursery we have a regimented maintenance program where we weed weekly to eradicate this weed and others . Where we go through all areas of our nursery routinely every seven days resulting in an almost weed free nursery.