yellow wood sorrrell also known as Creeping Oxalis

low growing weed Creeping oxalis Oxalis corniculata

distribution-of-creeping-oxalis-or-yellow-wood-sorrel-in-Australia

Creeping oxalis (Oxalis corniculata).

Name: Gilba Solutions Pty Ltd
Price range: $

Creeping oxalis (Oxalis corniculata) is a Winter annual or sometimes a perennial herb. It is also known as Yellow Wood Sorrel or Wood Sorrel, and is often mistaken for White Clover. However there are some distinct differences between them.

Why is Creeping Oxalis a Weed.

Once it establishes Oxalis corniculata can quickly spread.
It forms dense mats. These can choke out existing grass.
It competes with turf for soil nutrients and water.
This weed is difficult to eradicate due to its root system. It can spread by stolons.
The leaves are difficult to wet. This affects herbicide uptake.
The bright yellow flowers can be an issue.

The stolons of spread across the ground, and are up to 60 mm long. The hairy stems are light green to red purple. It has alternate trifoliate leaves its stems, that often cause it to be mistaken for White Clover.

Stolons of creeping oxalis

There are two easy ways to tell these weeds apart:

The Creeping oxalis flower is yellow. White Clover has pink or white flowers.
White Clover has a distinct white mark on its leaves. Oxalis corniculata doesn’t have this.

This weed is often mistaken for Soursob or Soursop (Oxalis pes-caprae). The main differences between them are:

Soursob doesn’t spread by above ground stolons. It reproduces via bulbs.
Wood Sorrel doesn’t have any underground bulbs.
The flowers of Soursob are larger.
Soursob favours heavy, fertile, well-drained soils, and areas not prone to frost. Creeping oxalis is more frost tolerant.
Soursob flowers mainly in the Winter, and is dormant over the Summer.

The leaves of this weed have a lemon flavour. You can use these to make a Vitamin C rich tea. However, it contains large amounts of oxalic acid (hence its name) which blocks calcium absorption in the body.

How to Identify Creeping oxalis.

It has three heart-shaped leaves and bright yellow flowers.

Photosynthetic pathway: It is a C3 weed.

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

Height: This weed grows from 10 to 35 cm tall.

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

Leaf width: The leaves are 11 to 24 mm wide.

Reproduction: This weed reproduces by seed, and also spreads by stolons. The seeds travel up to 5 metres out of seed pods. They then can be carried on shoes, fur and machinery.

The seeds germinate very quickly, and eventually a carpet of oxalis occurs.

Creeping oxalis (Oxalis corniculata) yellow wood sorrel seed pod

Creeping oxalis (Oxalis corniculata) seed pod

Comments: The leaves have a cover of coarse hairs.

Habitat: This weed is a good indicator of soil problems. It prefers moist soil, and partial shade, and is tolerant of drought.

More weed information is in our Weed ID Chart.

How to Control Creeping oxalis.

You can attempt cultural and chemical control of this weed, but cultural control is very difficult.
That’s why an integrated approach is the best approach.
However, once this weed establishes it is difficult to control.
Autumn is an ideal time to control of this perennial weed.

Cultural Control of Creeping oxalis.

Both hand removal, and mowing do not work to control Yellow Wood Sorrel.

It can regrow from its deep tap root. If you hand weed, you must not leave any plant material behind in the soil.
At a low height of cut it takes on a prostrate growth habit.

Weed Management Calendar for Creeping oxalis.

Management Calendar for Creeping oxalis
Winter Annual sometimes Perennial
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Germination
Active Growth
Flowering
Fruiting
Pre emergent herbicide
Post emergent herbicide

Chemical Control of Creeping oxalis.

There are several herbicides to control Yellow Wood Sorrel. As this weed is difficult to wet, use Optispread 1000 to give good chemical contact with the weed.
For large infestations, a combination of pre and post-emergent herbicides is the most effective.
Pre-emergents prevent seed growth. You use post-emergents once weeds emerge. Post-emergents are often more effective on small weeds, rather than older, more mature ones.
Pre-emergents will not work if stolons, rhizomes, or root and stem fragments are left behind when you hand weed.

Pre-Emergent Herbicides for Creeping Oxalis.

BASF Freehand Herbicide
Echelon Duo.
Indaziflam. This gives good pre and post emergent control in 2020 work.

Table of Pre-emergent Turf Herbicides.

Product	Active	Group	Rate/ Ha	African Love grass	Annual Rye	Crabgrass	Creeping oxalis	Parramatta Grass	Paspalum	Summergrass	Winter Grass	Crowsfoot	White Clover	$ Cost / m2	Longevity weeks
Barricade	Prodiamine	3	1 to 4 L											143-572	24
Onset 10GR	Prodiamine	3	50 to 150 Kg											275-825	24
Echelon Duo	Oxadiazon	14	300 to 400 Kg											2100-2800	12
Dimension	Dithiopyr	3	1.75 to 3.5L											280-560	18
Freehand	Pendimethalin + dimethenamid-P	3 + 15	100 Kg											1585	12
Specticle	Indazaflam	29	250 ml											495	32
Pennmag	Metolachlor	15	2 L											45	8

Post Emergent Control of Creeping Oxalis.

Products that contain 2,4-D give the best results vs this weed.
The Sulfonylureas like Recondo and Duke, are also effective against this weed.
The best time to use post-emergents is in daylight hours. This is because its leaves fold downward towards the evening.
This is called nyctinasty. You can also see this in Gazania and Morning Glory.
When the leaves fold it makes it hard for chemicals to stick to the leaves.

Post emergents include:

Dicamba. Do not use on Buffalo grass.
Pylex. Do not use on warm season turf. Use this on actively growing Wood Sorrel. In some cases a single hit of Pylex may not give complete control. In this case you may need to repeat this 21 to 28 days later.
Warhead Trio. This is safe on Buffalo grass.
Stature Herbicide. Do not use this in the home garden.
Recondo Herbicide. Do not use this on Buffalo grass.
Weed Blast MA. This is safe on Buffalo grass.
Contra M. Do not use this on Buffalo grass
Duke Herbicide. This is safe on most Buffalo varieties.

Table of Post Emergent Herbicides for Creeping oxalis.

Product	Active	Chemical Group	Rate/Ha	Comments
Casper	Prosulfuron + Dicamba	2 and 4	800g-1Kg	Apply from Autumn to Spring. Use high rates in cool months or if high weed pressure. Control takes 4 to 6 weeks. Use an NIS at a rate of 0.25 to 0.5% v/v.
Contra M.	Dicamba + MCPA	4	6.5 L	Apply in 250-400L water. DO NOT use on Buffalo grass. After use do not mow for 2 days before or after application or fertilize within two weeks.
Dicamba	Dicamba	4	1.2L + 3.2L of 2,4-D Amine 625g/L	Use a minimum of 1000L/Ha water. Do not spray on Buffalo or Bent Grass.
Duke	Iodosulfuron	2	100g	Always use an NIS or Overtake Oil. Use in 200-500 L/ha water.
Pylex	Topramezone	27	0.375 mL/ 100 m2 in 4-6 L water + 0.5% MSO	Make two applications 21-28 days apart. You may see bleaching of Bentgrass after 7-14 days. Do not water for 24 hrs post application.
Recondo	Trifloxysulfuron	2	225g	Use an NIS at 0.25% v/v (1000 g ai/L), 0.42% v/v (600 g ai/L) or Overtake Oil at 1%v/v. Ensure uniform placement onto leaves & into crowns. Water volume is 400 to 800 L/ha. You may need a repeat application in 4 to 6 weeks. Allow at least 6 weeks before overseeding. You may see discolouration on Qld Blue and Zoysia.
Warhead	MCPA + Clopyralid + Diflufenican	4 + 12	5 L	You may see discolouration on kikuyu, carpet grass and Queensland blue. Avoid overlapping. Use an NIS.
Weed Blast MA.	Bromoxynil + MCPA	6 + 4	3-6 L	Apply in a minimum of 500L/Ha water. DO NOT mow for 2 days after treatment.

Non Selective Control of Creeping oxalis.

Glufosinate-ammonium provides weed control for 4 to 6 weeks. However, Oxalis corniculata will grow back due to the limited movement of this chemical.
Glyphosate. You can use Glyphosate. However, if water quality is an issue then use ProForce Manta Ray.

The chemicals below are non-selective. They also have a long term residual and stop re-growth of Yellow Wood Sorrel.

Renegade. Renegade stops germination of Oxalis corniculata for up to 12 months. This reduces the need for repeat chemical applications.
Numchuk Quad. This gives post and pre emergent control for up to 12 months.
Cortex Duo. Cortex Duo gives a rapid knockdown of this weed. It has a residual control of up to 3 months. It is also safe to use near trees.

Table of Non Selectives for Creeping oxalis.

Product	Active	Group	Rate/Ha
Glufosinate 200	Glufosinate-ammonium	10	1 to 6 L
Rapid Fire 800	Glyphosate	9	0.9 to 1.35 Kg
Numchuk Quad	Terbuthylazine + Glyphosate + Amitrole Oxyfluorfen	5 + 9 + 34 + 14	20 to 25 L
Cortex Duo	Nonanoic Acid + Oxyfluorfen	14	7 L/1000L
Renegade	Bromacil	5	3.5 to 6.5 Kg