Those of us that need to control wild onions in Bermuda, Zoysia or Centipede lawns can use IMAGE herbicide.
Wild onions are difficult to kill because of their bulb-type root system. The bulb stores more energy than other root systems. This root system is combined with a relatively small leaf, defending it from traditional herbicides, such as Round-Up and Weed-B-Gon, which must enter through the foliage to kill.
IMAGE controls nutsedge, wild onion, dandelion as well as certain grassy weeds in these lawns any time of the year.
Carefully read and follow the label instructions. Mix IMAGE 2.5 oz. per gallon of water and apply to the soil around the weed and allow it to dry for 24 hours. Rainfall or irrigation within the following 7 days will complete the application, washing the herbicide down to the root of the weed. IMAGE enters through the root system of the weed and will kill it within 5 weeks. Multiple applications may be necessary with onions, but IMAGE is your best weapon against wild onions.