I feel your pain, Teresa! In addition to wild onion, my yard is infested with wild violets too. I have been told by two different extension agents that nothing will kill wild violets, but I have been able to control them in my daylilies (but nowhere else in my yard) by continually pulling them up whenever I see a little plant. Unfortunately, I cannot say the same thing for wild onion. As you know, unless you actually dig them up 6 or more inches under the surface of the ground they just break off and then you get even more of the darn things.
I recently did a search through many, many herbicides to see if anything would touch either of these unwanted plants. Interestingly, I found two that list both wild onion and wild violet as affected weeds. Both are primarily listed as selective lawn weed killers (post emergents).
1. Quinclorac - Apparently this product is available under a couple of names and is also available blended with other herbicides. It is also the less expensive of the two. However, it has a lot of limitations. There are several grass types that this material can NOT be used on, including both some warm season grasses (centipede, St. Augustine and others) and cool season grasses (bentgrass and others) and will kill many broadleaf weeds including clover and dichondra. It is also mentioned on the label to keep it away from ornamentals, trees, groundcovers, etc.)
2. Imazaquin (Sold as "Image for Nut Sedge." The company also sells atrizane which is also sold as "Image with atrazine" or "Image for crabgrass." Image for Nut Sedge is recommended for most (not all) warm season grasses and is sold as a herbicide for various types of sedges as well as for crabgrass. However, on the label it lists wild onion along with the various sedges. It only lists wild violet as a weed that the product "will aid in the control of," and "may take more than one application." It also notes that wild onion may also take more than one application. While it says it can be used "over the top" on some ornamentals, daylilies are not on that relatively short list. I think they recommend the use of a non-ionic surfactant when being used for weeds with waxy leaves which both wild onion and wild violet have.
I have not purchased either product at this point, so I am obviously not recommending either. Nevertheless, since I have both wild onion and wild violets, and have centipede grass, if I do purchase it will have to be Image, and if used in my daylily beds, it will have to be done while shielding the daylilies from the spray - - which won't be easy. I just wonder if it would be easier in the long run to pull off the green portion of the onion until fall, making sure none bloom, and then pot up all the daylilies from that worst areas, spray the onions a couple of times, wait until early spring the next year, spray more and then re-plant the daylilies in early-to-mid April in time for bloom season. Wow, that makes me tired just thinking about it!
From my viewpoint, there still isn't a good answer other than "dig them up", but there is at least an ugly option if you might want to try it.
Larry
Those little bulblets don't take long to establish and start the process all over. It was a hasty fall job and I piled them on my (rural) driveway intending to dispose of them later and found myself preoccupied with more desirable projects. The next spring I had a big, green mound of wild onions to deal with. Luckily they were concentrated on gravel for easy kill and removal.
