I have the lesser celandine, too. After conferring with a scientist working with my county I have resorted to 53% glyphosate application. I’m in my 3rd year with it and making some progress. I apply it with a foam paint brush. Never in windy conditions, never if it is blooming. I’ve battled lots of invasives but this one is, by far, the worst. We need a support group. My friends avoid me in early spring because all I can talk about is how much I hate the stuff.

I was just seeing some progress on poison ivy and was ready to tackle buckthorn and then… lesser celandine took over my weed radar. And our parkway. And is clearly creeping into our property. The advice I’ve been given sounds akin to napalming half of our property, and I’m not ready to do that, but hand weeding sounds arduous. But perhaps a combination (herbicide on parkway, hand weeding in areas where there are also lovely patches of trillium and other natives)? I’m in Lake County, IL 5b/6a.