How can I kill the wild onions in my flower beds?

I put the black weed blocking material down thouroghly and then mulched deeply. I keep spraying these things with Round-up and it doesnt even bother them. How can they grow through the wedd material? I was sure to cover all holes before mulching. Any Ideas? I cant pull them up or dig them up or I will tear the material.

How can I kill the wild onions in my flower beds?
To really be free of them, you will need to remove them. By digging them up. They are tough little buggers, and pulling them won't work. You've got to remove that knob in the roots.





Remove your landscaping cloth. Dig them out with a shovel, getting a genrous amount of dirt with them to make sure you get the roots. Then take them by the strappy leaves, and bash the root ball against the back of the shovel (very satisfying since they're been your nemesis for so long), letting the extra soil go back in the garden. Put the weeds in the trash.





Replace the landscape fabric, and congratulate yourself on a difficult battle, well fought, and victorious.
Reply:Sorry to say, but digging them up is the only way I've ever had any luck at getting rid of onions. Like you said, Round Up doesn't seem to do much at all to them.





That weed cloth, as I've learned, won't actually stop a lot of things from growing through it. I've ripped out all the weed cloth I put in just because of that and just went with a little thicker layer of mulch. That way I can just move the mulch to dig out the rare stuff that grows through.





The only thing I've every found that actually stops stuff from growing is thick sheeting like pond liner, or big rocks. The problem with that is that you can't cover any roots of bushes or trees with it because water won't go through it either.





I guess you could put a three or four inch layer of gravel on top of the weed cloth, that would probably stop the onions from getting through. It would be a nightmare later on though if you ever decided to take it out. Not something I would do, personnaly.