It is probably a good idea to go the plastic route. I read on another forum that the only success to be had was just what you are doing, including the round up on anything green that shows its's face. I am not a fan either but have tried it on these things. This year i tested it in an area that is barren except for them. I found that if you get them just as they are arching out of the ground (sticking their noses up, lol!) they do die back. Not sure yet what the bulbs look like but I will be digging to see after some time passes. Once the leaf or leaves are up, it is really hard for the round up to do it's work. Last year, I cleared a bed and bagged all the turf grass into black plastic contractor bags, hoping to compost it over the year. I opened them almost exactly a year later and guess what was the only thing growing, in the total darkness? Yep. I've (unfortunately) continued digging like a gopher. I've got them in perennial beds where I can't spray, but I have been trying to be vigilant for months now, digging at first sign, and picking the balls of the surface as far back as march. I've got pockets of them that I keep my eyes on the most and am really, really trying to get them gone. I dug up one whole 7ft or so bed totally this past month. Everything growing there was removed and put in quarantine. It was one of the worst areas yet the one that needed the most work, so thought I would try it. Nothing that really needed saving was growing there, though I did save the stuff. I manually picked out patches and sifted all the dirt thru a window screen. What hell. I went down as far as the topsoil seemed to go till I got to compacted rock and clay, and just re-filled it last week so time will tell. I want to put perrenials there, but am holding off till I feel it is under control. I spread a bunch of zinnia seeds there this season for the time being. I'm afraid to transplant anything around the yard for fear of moving them to "clear zones". The stuff I have transplanted I have essentially washed off the roots to bare root and replanted. I have discarded lots of soil, sadly, and have lots of low points and divots, but it seems that when they pop from these areas I can get them up from the disturbed soil. I'm going to let these areas around my plants alone before I refill, and see if I can eliminate them that way, too. Keeping a watchful eye on known areas and dig every night in known areas. I saved a bunch in pots (in a safe place, if there is one, lol!) to test what cutting the leaves off, roundup and covering totally will do to them. The front lawn is just filled with the immature leaves currently. As I walk down the street there are 3 places offhand that I know are filled with a field of them, mature flowering plants. Good luck and keep me posted. I feel so alone in this fight. I'm on my way back outside to do daily rounds of search and dig. I may spray some in the front yard that were sprayed a week ago. I try and pull the trigger on the foam setting right on top of each one, no broadcast spraying. I don't think broadcast spraying would even work, not concentrated enough. I just now deflowered several that I spotted growing under the hedges out front. Crafty buggers, they are. By the way, keep a long screwdriver handy while you work. It's good for lifting out strays you find as you work!