Oxalis Management

LayLa Burgess,
Urban Horticulture Extension Agent,
Clemson University Cooperative Extension Service

HTG 0917

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Oxalis or yellow woodsorrel (Oxalis stricta) is a common cool-season perennial weed that persists almost year-around in Southeastern lawns. It grows sporadically in landscape beds among shrubs and flowers, in vegetable gardens, and is known to pop up occasionally in container plantings.

Oxalis (O. stricta) can be pulled up by the hand easily when found growing intermittently in landscape beds.
Oxalis (O. stricta) can be pulled up by the hand easily when found growing intermittently in landscape beds.
LayLa Burgess, ©2017 HGIC, Clemson Extension

Oxalis has an upright form with slightly hairy stems that branch from the base of the plant at almost ground level. Erect stems give rise to an alternate leaf arrangement. Oxalis stricta leaves are green, whereas the commonly found creeping woodsorrel (O. corniculata) has green to purple leaves. Oxalis leaves are distinctly trifoliate (leaflets of three) with a heart shape similar to the leaves of clover. Often the leaves will fold along the midrib and hang down in the heat of summer, in intense light, and at night. Oxalis produces 5-petalled yellow flowers singly or in clusters on a branched stalk. Small okra shaped fruiting capsules are formed that contain minute seeds. When mature, seeds are ejected from the capsule for a considerable distance from the parent plant. Oxalis reproduces primarily by seed, but may spread by underground slender rhizomes.

Oxalis (O. corniculata) often invades container flowerpots, but can be easily removed by hand pulling. Oxalis produces a 5-petalled yellow flower followed by a seed capsule.
Oxalis (O. corniculata) often invades container flowerpots, but can be easily removed by hand pulling. Oxalis produces a 5-petalled yellow flower followed by a seed capsule.
LayLa Burgess, ©2017 HGIC, Clemson Extension

Oxalis grows under a variety of conditions, but prefers moist fertile soils and full sun. It will tolerate shady areas. All plant parts are poisonous because of the production of soluble oxalate, but are only mildly toxic and generally causes little problem if ingested.

Cultural Control

Oxalis flowers and produces seeds heavily in the spring and summer, but can produce both all year long. Small plants can easily be handpicked or dug as they appear before they flower or form seed. Removal of all vegetative portions of the plant, including roots and rhizomes, is important. Rhizomes can be easily removed when soil is moist. Do not place the weeds with seeds in compost bins for reuse in the landscape.

A light layer of mulch in landscape beds and around flowers and shrubs will aid in preventing further germination of oxalis seeds. The seeds require light for germination, so limiting light to the seedbed with mulch will reduce the numbers of new oxalis plants. 

Oxalis forms a fruiting capsule that contains multiple seeds.
Oxalis forms a fruiting capsule that contains multiple seeds.
LayLa Burgess, ©2017 HGIC, Clemson Extension

Maintenance of healthy, dense lawns will create less space for oxalis to invade. Lawn maintenance should adhere to fertilizer and lime recommendations obtained from proper soil testing combined with proper mowing height and frequency requirements. For more information on soil testing, see HGIC 1652, Soil Testing.

Chemical Control in Landscape Beds

In landscape beds, a non-selective herbicide containing glyphosate is the best choice for spot treatment of oxalis. Apply glyphosate spray to thoroughly wet the foliage of the weeds. Target oxalis seedlings and young plants (before the flowering stage) for best results. Examples of products containing glyphosate are listed in Table 1. Always read product labels for safe use around landscape ornamentals and established perennials.


Table 1. Examples of Products Containing Glyphosate in Homeowner Sizes.
Active IngredientProduct Name
glyphosate Roundup Original Concentrate
Roundup Pro Herbicide
Martin’s Eraser Systemic Weed & Grass Killer
Quick Kill Grass & Weed Killer
Bonide Kleenup Weed & Grass Killer 41% Super Concentrate
Hi-Yield Super Concentrate
Maxide Super Concentrate 41% Weed & Grass Killer
Super Concentrate Killzall Weed & Grass Killer
Tiger Brand Quick Kill Concentrate
Gordon’s Groundwork Concentrate 50% Super Weed & Grass Killer
Zep Enforcer Weed Defeat III
Eliminator Weed & Grass Killer Super Concentrate
Monterey Remuda Full Strength 41% Glyphosate
Southern States Grass & Weed Killer Concentrate II
Total Kill Pro Weed & Grass Killer Herbicide
Ace Concentrate Weed & Grass Killer

Chemical Control in Lawns

For small numbers of oxalis plants scattered throughout the lawn, a spot treatment with a recommended postemergent herbicide may provide adequate control. For larger oxalis infestations in the lawn, preemergent and postemergent herbicides may be necessary. Preemergent herbicides prevent seed growth, whereas postemergent herbicides are applied to foliage of the weeds once they emerge. Postemergent herbicides are often more effective at killing smaller weeds rather than older, mature ones.

Preemergent and postemergent herbicides for oxalis (yellow woodsorrel) control in South Carolina lawns are listed in Tables 2 and 3. Always read the product label for mixing rate for weed control on each grass species and for safe use of the product. Preemergent herbicides need to be applied at the proper time of the year, may require one or more subsequent applications, and need to be watered in appropriately. For more information on preemergent herbicide use, see HTG 0217, Selecting a Preemergent Herbicide for your Lawn. When using a postemergent herbicide, spray to just wet the foliage of the weeds. For safe use on lawns, spray herbicides when temperatures are below 90 °F. Avoid pesticide drift by spraying on non-windy days. Water the lawn the day before to reduce drought stress to lawns and to promote active growth of the weed for better herbicide uptake.


Table 2. Preemergence Herbicides for Oxalis Control in Home Lawns.
TurfgrassActive IngredientsExamples of Brands & Products
Notes: These preemergence herbicides should only be applied to well-established turfgrass lawns. Typically, the optimum time for lawn fertilizer applications and pre-emergence herbicide applications do not coincide. However, the small amount of potash in the 0-0-7 blends is normally not a problem, & may be useful on sandy soils with fall applications to improve cold weather hardiness of the lawn.
Bahiagrass Bermudagrass Centipedegrass
St. Augustinegrass Zoysiagrass
Tall Fescue
benefin Pennington Crabgrass Preventer
oryzalin Southern Ag Surflan A.S.
benefin +
oryzalin
XL2G
Green Light Amaze Grass & Weed Preventer
benefin + trifluralin

Anderson Turf Products Crabgrass Preventer with 2% Team Herbicide (partial control)
Hi-Yield Crabgrass Control (partial control)

pendimethalin Scotts Halts Crabgrass Preventer
dithiopyr Bonide Crabgrass & Weed Preventer for Lawns & Ornamental Beds
Hi Yield Turf & Ornamental Weed & Grass Stopper Containing Dimension
StaGreen CrabEx Crabgrass Preventer
isoxaben Ferti-lome Broadleaf Weed Control with Gallery
prodiamine Helena Pro-Mate Barracade & Fertilizer 0-0-7
Howard Johnson Crabgrass Control with Prodiamine & 0-0-7
Lebanon Pro Fertilizer (0-0-7) with Prodiamine
Lesco Barricade Plus Fertilizer 0-0-7
Lesco Stonewall Plus Fertilizer (0-0-7)
Pro-Mate Barricade Plus Fertilizer (0-0-7)
Scotts Halts Pro 0-0-7 & Halts Pro

Table 3. Postemergent Herbicides for Oxalis Control in Home Lawns.
TurfgrassActive IngredientsExamples of Brands & ProductsEffectiveness
1For use on common bermudagrass. Intermediate safety on hybrid bermudagrass.
2Use low rate on zoysiagrass.
Effectiveness Rating:
Poor – P = <70% control
Fair – F = 70-79% control with repeat applications
Good – G = 80-90% control with one application at high rate or repeat application
Excellent – E = >90% control with one application
Centipedegrass
St. Augustinegrass
atrazine Hi Yield Atrazine Weed Killer
Image for St. Augustinegrass & Centipedegrass with Atrazine
Southern AG Atrazine St. Augustine Weed Killer
Spectracide Weed Stop for Lawns Concentrate for St. Augustine & Centipede Lawns
Fair to Good Control
Bahiagrass
Bermudagrass
Centipedegrass
St Augustinegrass
Zoysiagrass
Tall Fescue
2, 4-D + dicamba + mecoprop (MCPP) Ferti-lome Weed Out Lawn Weed Killer with Trimec
Southern Ag Lawn Weed Killer with Trimec Conc.
Good Control
Bermudagrass1
Zoysiagrass
Tall Fescue
sulfentrazone +
quinclorac
Image Kills Crabgrass Concentrate Good Control
Zoysiagrass2
Tall Fescue
triclopyr Ortho Weed B Gon Chickweed, Clover & Oxalis Killer Fair to Good Control
Tall Fescue triclopyr Hi-Yeild Triclopyr Ester
Monterey Turflon Ester
Fair to Good Control
Bahiagrass
Bermudagrass
Zoysiagrass
Tall Fescue
MCPA +
dicamba +
triclopyr
Monterey Spurge Power Concentrate
Bonide Chickweed, Clover & Oxalis Killer Concentrate
Good Control
Bermudagrass
Centipedegrass
St Augustinegrass
Zoysiagrass
metsulfuron Martin’s TopShot Weed Killer for Lawns Fair to Excellent Control

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This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.