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Virginia Buttonweed

Virginia buttonweed (Diodia virginiana) is a mat-forming perennial that thrives in poorly drained areas or under excessively moist soil conditions in lawns. Leaves are lance-shaped and dark green. Close-up of Bugwood photo 1604118. John Ruter, University of Georgia, Bugwood.org

Virginia buttonweed (Diodia virginiana) is a mat-forming perennial that thrives in poorly drained areas or under excessively moist soil conditions in lawns. Leaves are lance-shaped and dark green.
Close-up of Bugwood photo 1604118. John Ruter, University of Georgia, Bugwood.org

Virginia buttonweed (Diodia virginiana) is a challenging to control turfgrass weed that has recently become a prevalent weed in South Carolina lawns. This perennial weed is deeply rooted, produces belowground and aboveground flowers, and spreads by rhizomes (underground stems), as well as by stem pieces cut and distributed during mowing or string trimming. Virginia buttonweed becomes more troublesome and thrives in poorly drained or overly moist lawns caused by excessive rainfall or frequent irrigation.

Its shiny, dark green, lance-shaped leaves are oppositely arranged on the stems and have no petioles (stalks that attach leaves to stems). By late summer, leaves may turn yellow-green due to a viral infection. The flowers are tubular and white with four petals, which are arranged in a four-pointed star. If left uncontrolled, this mat-forming weed can smother out turfgrass.

The flowers of Virginia buttonweed (Diodia virginiana) are tubular, white, and have four petals. Close-up of Bugwood photo 5428015. Rebekah D. Wallace, University of Georgia, Bugwood.org

The flowers of Virginia buttonweed (Diodia virginiana) are tubular, white, and have four petals.
Close-up of Bugwood photo 5428015. Rebekah D. Wallace, University of Georgia, Bugwood.org

A close-up of some green leaves Description automatically generated with low confidence

During the late summer, many of the Virginia buttonweed (Diodia virginiana) leaves will become yellow-green and mottled because of an infection by an unknown virus.
Joey Williamson, ©2020 HGIC, Clemson Extension

Cultural Controls: Limit Virginia buttonweed growth by maintaining a healthy and dense turfgrass. Water the lawn deeply but infrequently to allow the surface soils to dry between watering, thus improving turfgrass root depth. For more information on irrigation, please see HGIC 1207, Watering Lawns. Additionally, correct any drainage problems to reduce wet areas within the lawn.

Core aerate the lawn to improve internal soil drainage, reduce soil compaction, and aid in root growth. For more information on core aeration, please see HGIC 1200, Aerating Lawns.

Apply fertilizers and lime based on soil test results. Fertilizer and lime recommendations are turfgrass specific. Please see HGIC 1652, Soil Testing, for sampling procedures.

Mow the lawn at the correct height for the turfgrass species. Mowing excessively low both stresses the turfgrass and causes the mower to cut and spread pieces of the weed’s stems. Virginia buttonweed tolerates mowing as low as ½ inch, and stem pieces can easily root under moist conditions. A lawn mowed at the correct height encourages dense turfgrass growth and helps shade out the Virginia buttonweed. For correct mowing heights, please see HGIC 1205, Mowing Lawns.

If the lawn thatch layer is greater than ½ inch, consider dethatching the lawn at the appropriate time. For more information about dethatching, please see HGIC 2360, Controlling Thatch in Lawns.

Hand pulling Virginia buttonweed is ineffective as a control because pieces of roots and stems that remain can re-sprout.

Chemical Controls: Managing Virginia buttonweed in a lawn may require two years of post-emergence herbicide applications. For best control, begin herbicide applications in the spring when the plants are coming out of dormancy and producing tender, new growth. Spring herbicide applications also help control the young seedlings growing in the lawn and prevent large mats of growth that can smother out turfgrass by late summer. In late summer, older Virginia buttonweed plants are much more tolerant of selective herbicides, making controls less effective.

Apply metsulfuron (Quali-Pro MSM) or Celsius WG sprays in the spring when the Virginia buttonweed begins to green-up. Apply a follow-up application four to six weeks later. These products are safe to apply when the temperature is greater than 85 °F. In contrast, products containing 2,4-D may injure centipedegrass or St. Augustinegrass above 85 °F. Metsulfuron (as the only ingredient in a product like MSM) or Celsius WG can be sprayed on weeds in warm-season turfgrass during the lawn’s spring green-up period. Celsius WG provides good to excellent control of Virginia buttonweed, while metsulfuron offers good control.

Blindside Herbicide WDG contains metsulfuron and sulfentrazone and may give better control of Virgina buttonweed than metsulfuron alone. Make a second application 21 days after the initial application.

Fahrenheit Herbicide contains metsulfuron and dicamba. Make a repeat application in 4 to 6 weeks for control. Do not make Fahrenheit application if temperatures will exceed 85 degrees.

Do not apply metsulfuron products or Celsius WG to a tall fescue lawn. Do not apply metsulfuron products beneath the dripline of trees and shrubs. Read all label precautions and restrictions.

Use 3-way lawn herbicides containing 2,4-D, dicamba, mecoprop, and carfentrazone on bermudagrass, centipedegrass, zoysiagrass, St.Augustinegrass, and tall fescue. However, only apply these products after warm-season turfgrasses have completely greened-up in late spring. The 2,4-D, dicamba, mecoprop, and carfentrazone combination herbicides will suppress new Virginia buttonweed growth in the spring and kill the seedlings. Do not make spray applications if the daily temperature is greater than 90 degrees. A second application can be made with most products after 30 days.

Treat large areas of Virginia buttonweed with little to no turfgrass with a 3% glyphosate spray. Read the label directions of forty-one percent glyphosate products for instructions on mixing in a pump-up sprayer. Re-sod a couple of weeks after the last glyphosate application once the Virginia buttonweed is eliminated.

See Table 1 below for brands and products, including more notes on the use of metsulfuron, Celsius WG, glyphosate, and combination broadleaf weed herbicides.

Table 1. Examples of Post-emergence Herbicides for Virginia Buttonweed Management in Residential Turfgrass.

Brands & Specific Products Herbicide
Active Ingredient
% Active Ingredient
in Product
Site Labeled for Use
Ferti-lome Weed Free Zone Concentrate; & RTS1 2,4-D
Mecoprop (MCPP)
Dicamba
Carfentrazone
10.49
2.66
0.67
0.54
Tall Fescue
Bermudagrass
& Zoysiagrass
Centipedegrass
& St. AugustinegrassAn application may be repeated once after 30 days.
Ferti-lome Weed Free Zone RTU2 MCPA
Mecoprop (MCPP)
Dicamba
Carfentrazone
0.3370
0.0660
0.0180
0.0023
Bonide Weed Beater Ultra Concentrate MCPA
Mecoprop (MCPP)
Dicamba
Carfentrazone
31.55
6.16
1.65
0.22
Gordon’s Trimec Speed Lawn Weed Killer Concentrate & RTS2 2,4-D
Mecoprop
Dicamba
Carfentrazone
4.01
0.49
0.27
0.16
Ortho WeedClear Lawn Weed Killer Concentrate; & RTS2 Concentrate 2 2,4-D
Mecoprop
Dicamba
Carfentrazone
4.01
0.49
0.27
0.16
Celsius WG Herbicide3 Thiencarbazone
Iodosulfuron
Dicamba
8.7
1.9
57.4
Bermudagrass
Zoysiagrass
Centipedegrass
& St. Augustinegrass4
Quali-Pro MSM Turf Herbicide5
(for professional use)
Metsulfuron 60.0 Bermudagrass
Zoysiagrass
Centipedegrass
& St. Augustinegrass
Blindside Herbicide WDG5
(for professional use)
Metsulfurone
Sulfentrazone
6.0
60.0
Bermudagrass
Zoysiagrass
Centipedegrass
& St. Augustinegrass
Quali-Pro Fahrenheit Herbicide5
(for professional use)
Metsulfuron
Dicamba
5.0
33.0
Bermudagrass
Zoysiagrass
Centipedegrass
& St. Augustinegrass
Ace Concentrate Weed & Grass Killer Glyphosate 41% (most brands) For use within the lawn as a spot spray to kill large patches of Virginia buttonweed.

Then re-sod or re-seed these areas after Virginia buttonweed is dead (a couple of weeks later).

Bonide Kleenup Grass & Weed Killer Concentrate; & RTU2
Weed Killer Concentrate; & RTU2
Eliminator Weed & Grass Killer Super Concentrate
Gordon’s Groundwork Concentrate 50% Super Weed & Grass Killer
Hi-Yield Super Concentrate Killzall Weed & Grass Killer
Knockout Weed & Grass Killer Super Concentrate
Martin’s Eraser Systemic Weed & Grass Killer
Monterey Remuda Full Strength 41% Glyphosate
Quick Kill Grass & Weed Killer
Roundup Original Concentrate
Roundup Pro Herbicide
Southern States Grass & Weed Killer Concentrate II
Tiger Brand Quick Kill Concentrate
Total Kill Pro Weed & Grass Killer Herbicide
Ultra Kill Weed & Grass Killer Concentrate
Zep Enforcer Weed Defeat Concentrate
1 RTS: Ready-to-Spray (hose-end sprayer)
2 RTU: Ready-to-Use (pre-mixed spray bottle)
3 This mix of active ingredients requires the addition of 0.25% by volume (2 teaspoons per gallon of water) of a non-ionic surfactant (such as Hi-Yield Spreader Sticker, Southern Ag Surfactant for Herbicides, or Bonide Turbo Spreader Sticker). This is a wetter-sticker agent to aid in weed control. Repeat Celsius WG application in 4 to 6 weeks for the best control.
4 Spot treatments of Celsius WG to St. Augustinegrass at temperatures above 90 degrees may cause temporary growth regulation. Celsius WP is not for use on fescue lawns.
5 Do not apply products containing metsulfuron to turfgrass that is less than one year old. Do not apply beneath the dripline of trees and shrubs.
Note: Do not apply any post-emergence herbicides, except Celsius WG Herbicide, to lawns during the spring green-up of turfgrass. For other products, wait until the turfgrass is fully green in late spring. Follow all product label directions for mixing and safe use.

If this document didn’t answer your questions, please contact HGIC at hgic@clemson.edu or 1-888-656-9988.

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