U-Z Weeds

Control of Common Weeds

Weeds are indexed alphabetically.  Select the section of interest.

A-E F-J K-O P-T U-Z

U-Z

Violets (Viola spp.)
Use products containing metsulfuron, triclopyr and clopyralid or triclopyr + 2,4-D.  Multiple applications 7 days apart are often required.  Partial control is with 2,4-D + 2,4-DP.  Mid- to late-fall applications are best followed by mid-spring to early summer. Manor/Blade (metsulfuron) is effective in bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass.

Virginia Buttonweed (Diodia virginiana)
Postemergence suppression is with 2-way or 3-way herbicides with 2,4-D, dicamba, + MCPP.  2,4-D is most effective, therefore, use combination products with a high concentration of it.  Repeat in 4 to 5 weeks. A combination of Corsair 75DF @ 3 oz/a + 2,4-D @ 0.5 lb ai/a, Millennium Ultra 3.75L at 2.5 pts/a, Monument at 0.56 oz/a + 2,4-D, or Confront 3L at 1 pt/a have worked well. Repeat in 60 days.

Wild Garlic/Onion (Allium sp.)
Image 1.5L at 2 pts/a in December. Repeat with 1 pt/a in early March. Add 0.25% nonionic surfactant (1 qt/100 gal water). Also, 2,4-D LV ester alone or two- or three-way combination products. Treat in November, March, and again the following November. Monument, Corsair, and Manor/Blade also work well. In dormant turf, Roundup Pro 4L at 1 pt/a plus Trimec Classic at 3.5 pt/acre, repeat in 3 to 4 weeks.

Yellow Nutsedge (Cyperus esculentus)
Monument 75 DF (trifloxysulfuron) at 0.56 oz/acre or Certainty 75 WDG (Sulfosulfuron) at 1.25 oz/acre in bermudagrass and zoysiagrass. Make a repeat application, if regrowth appears. Add 0.25% nonionic surfactant. Basagran T/O (bentazon) may be used at 0.75 to 1.5 fl oz/1,000 sq ft or 2 to 5 pt/acre at the four- to six-leaf stage of nutsedge growth. Apply when the temperature is at least 75 F. Add crop oil or surfactant to Basagran. Complete coverage is essential. Repeat the application in 7 to 10 days.  Do not apply more than 6 pt/acre of Basagran in one season. Sedgehammer 75 DF (halosulfuron) is effective on purple nutsedge, yellow nutsedge and kyllinga and should be applied to nutsedge in the three- to eight-leaf stage at 1.33 oz/acre. Make a second application in four to six weeks or when regrowth appears. Add 0.25% nonionic surfactant. Do not mow for two days before and two days after application.

For spot treatment, mix 0.9 gram of Sedgehammer in one gallon of water with 1/3 fl oz nonionic surfactant. Image 70 DG (imazaquin) is an effective herbicide for suppressing purple or yellow nutsedge in turfgrass. It is approved for use on bermudagrass, zoysiagrass, St. Augustinegrass and centipedegrass. The recommended rate is 0.26 oz of product per 1,000 sq ft. (11.4 oz/acre). A repeat application will probably be needed for full-season suppression. Make the repeat application in four to six weeks or when regrowth appears. A tank mix of Image + 2.0 lb/acre MSMA has given better suppression than either product alone. Do not use the MSMA tank mix on St. Augustinegrass or centipedegrass. Image + MSMA will cause longer-term injury to zoysiagrass than bermudagrass. ‘Meyer’ and ‘El Toro’ are more tolerant of MSMA than ‘Emerald’ or ‘Matrella’ zoysigrasses. Back to Index.