yellow wood sorrrell also known as Creeping Oxalis

distribution of creeping oxalis, or yellow wood sorrel in Australia

Creeping oxalis (Oxalis corniculata).

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Creeping oxalis is an annual or sometimes perennial herb, and is also known as Yellow Wood Sorrel or Wood Sorrel. It is a troublesome weed of gardens and lawns, and forms dense mats in lawns that choke out turf.

Creeping oxalis has stolons that that creep above the ground, and may be up to 60 mm long. The stems are light green to reddish purple, hairy, and slightly succulent. Trifoliate leaves alternate along these stems.

It is often mistaken for Soursob or Soursop (Oxalis pes-caprae). The main difference is that Soursob does not have creeping above ground stems and reproduces mostly via underground bulbs. Wood Sorrel does not have underground bulbs. This flowers mainly in Winter and goes dormant over the Summer.

Another way to distinguish these weeds is that Soursop grows well in heavy, fertile, well-drained soils and tends to favour areas not prone to frost.

The leaves have a lemony flavor and are often made into tea that’s rich in vitamin C. However, if ingested in large amounts the oxalic acid for which the genus is named can begin to block the body’s calcium absorption.

This discusses the cultural and chemical options to remove Creeping oxalis from your lawn and turf areas.

How to Identify Creeping oxalis.

Creeping oxalis has three heart-shaped spotted or marked leaves and bright yellow flowers.

Flower: Yellow Wood Sorrel has yellow flowers with five petals that are 4 to 5 mm in diameter. It flowers from September to April.

Height: It grows to a height of 10 to 35 cm.

Leaf length: The leaves of Wood Sorrel are egg shaped, and 4 to 13 mm long. Each leaf has a distinct notch at the end of it.

Leaf width: Leaf width is 11 to 24 mm.

Reproduction: This weed reproduces by seed which germinates quickly. It also spreads vegetatively. The seeds are thrown up to 5 metres out of seed pods, and are easily transported, as they are angled and slightly rough. This allows them to stick onto shoes, fur and machinery.

Comments: The leaves are covered in coarse hairs.

Habitat: Creeping oxalis is a good indicator of soil problems. It prefers moist soil, and partial shade, tolerates drought, and is tolerant of a wide range of conditions. More weed information is in our Weed ID Chart.

Unlike many oxalis species, Wood Sorrel doesn’t have underground bulbs, but is able to reproduce vegetatively via a very efficient system of stolons. It allows Creeping oxalis to rapidly spread to form dense mats over turf.

How to remove Creeping oxalis from your lawn.

Although you can attempt cultural and chemical control to remove Creeping oxalis or Yellow Wood Sorrel, cultural control is very difficult.

Cultural control of Creeping oxalis:

The deep tap root means if you hand weed, and leave any plant material behind in the soil it regrows.
Under close mowing it assumes a prostrate growth habit.

Chemical control of Creeping oxalis.

There are several turf herbicides that control Yellow Wood Sorrel. As Creeping oxalis is difficult to wet, we suggest you use Optispread 1000 to ensure good herbicide contact with the target weed.

Pre Emergent Herbicides for Creeping Oxalis.

Post Emergent Control of Creeping Oxalis.

Products that contain 2,4-D usually provide the best results vs Creeping Oxalis. Apply post-emergent herbicides to Wood Sorrel in daylight hours as the leaves fold downward towards the evening. This is called nyctinasty, and you can also see this in Gazania and Morning Glory.This then makes it difficult to get herbicides to stick to the foliage.