Q.My Neighbor’s Mint Is Coming Under The Fence And Choking Out My Rose Bushes.
Last year I had hip surgery and the mint got a head start as I didn’t keep on top of it. Now I have been digging it out and find the roots are well established. What I would like to know is there something I can put on the exposed roots that won’t harm my roses? Or do I just have to keep digging?

Certified GKH Gardening Expert
You can put a barrier in the ground between the fence and your roses to keep any more from coming over, because they will. Then keep digging till you get it all out. You can shield your rose bush with a thick piece of cardboard and spray the mint with an herbicide if you don't want to dig. You also can cover the mint with sheets of newspaper or cardboard, then cover it with mulch. That should kill it out.
https://www.gardeningknowhow.com/edible/herbs/mint/invasive-mint-how-to-kill-mint-plants.htm