Omg, I’ve been working on this at our new home in Philadelphia. They’re so bad. So far, I’ve pulled them all out by hand (which takes forever). My plan was to use mulch but I’ve read you need at least 4” deep, which brings other problems like vermin and mold. Ridding a garden bed of wild onion grass completely will take years. If you pull them up (as opposed to using herbicide), you need to pull them carefully as the bulbs are tiny. Pull the entire clump out, don’t shake excess dirt off cause it will just spread them back in. Dispose of them in a yard bag, don’t compost.
☰