You found out that alliums in general are pretty herbicide resistant. First don't let any of them bloom or set bulbils again. Second count on digging them out every year for several. You might contact your local county extension agent or state agricultural college for recommendations for a more effective specific herbicide. If you do dig them out, put them into the trash not into a compost pile.

Sorry there is no easy way to control runaway alliums, which is why so many of them are considered invasive noxious weeds by so many states. If you have the time repeated tilling or plowing as they start to resprout will likely reduce them, but you have to be willing to keep the dirt bare and worked up for quite some time.

Of course you could probably eat them, once they leech out the weed spray. Funny how things that become useful very often become delicate...

Yes, thank you.
Digging them out after 13 years hasn't proved successful.
As you might have experienced (and why tilling them is a BIG waste of time) even the tiniest bit of bulb becomes a MONSTER clump.

Ironically, I don't care if they're in the lawn. They stay green, I can mow them and done. And I don't really care about the brief onion smell. But these are 3 acres+ of onions, to the point it looks like my gardens have a nice lawn. Eating them? I barely cook, and other than vats of onion soup, could never use this many onions IN MY LIFE.

I just remember as a kid, knowing that if your cows got into some wild onions it would ruin their milk. Am I dating myself? Hmmm...

I appreciate you taking the time to post.

I once had a small garden that was LOADED with the bulbing type of oxalis. Quarter inch bulbs that were sometimes 2 feet down. I finally got fed up and just dug the whole place up and sifted every bit of dirt. Worked.

Yeah, chilipeppa. Let me get started on that 3 acres.... LOL!
No, really. I get it. Every time I plant something, I dig out onion after onion, clump after clump. Seems like it doesn't matter. Just wish it were growing in the lawn. Nice and green and thick.

I picked up some try.... something that's a brush killer. It was recommended in the Bulb forum. I don't it's going to work, but who the heck knows.

This link from Clemson might be of interest.

It seems to be specifically about lawns but it does give several recommendations for herbicides. It also says that cutting the foliage before application helps.

Rodney

One trick I have heard to counter the waxy stems of the alliums is to add a bit of garden soap to the mixture to help it stick.