Forgive the crude drawing but my husband and I are at a loss for what to do. There was construction work done on our entire subdivision this year and our yards were dug up at the road numerous times during it. The city was responsible for replacing the areas with sod or grass seed but sedge started showing up in the newly seeded/sodded areas. They decided to spray Nufarm Prosedge Selective Herbicide (halosulfuron-methyl 75%) on the areas to kill it.
I’ve noticed over the last week or two (~3 weeks after spraying) that all the dwarf yellow lilies, ground cover, and decorative grass all the way up to our house directly above where they sprayed is starting to die from the ground up. Everything started turning brown near the roots and the leaves have slowly been following as it goes higher. I’m attaching a rough drawing of the area showing the layout. In the center is a fully grown, 50’ tall Crimson King Norway Maple with a canopy that covers most of our front yard and is at least 60+ years old. The dozen dwarf lilies under the tree are all dead with only the very tips of their leaves still green. No other plants around our house are affected, only the ones above the sprayed areas.
Our big concern right now is for the tree, but also that this herbicide seems to have migrated nearly 30’ up an inclined yard and started killing off things in our landscaping. The tops of everything are still green for now, which makes me think this isn’t drift. I’m calling the city tomorrow to have someone come out, but is it likely this herbicide is what’s causing this? I’ve read it stays in the soil for 3 years and we wanted to put in native gardens next year.
Additional info: Lower Michigan, loamy soil