I really don't think there is anything that will do what you want it to.

I regularly spray RoundUp on ditch lillies to kill undesirable weeds. The ditch lillies survive, but they don't thrive. Of course, I consider that a good thing.

THe problem is that the lilies will come up before the bindweed.

Last year I had a bad case of bindweed in a perennial bed, and I dug up all the plants, sprayed the bindweed with concentrated roundup, then replaced the perennials, some of which survived.

This year, the bindweed is back.

Thank you for the replies. I definately want to keep the lilies because they start at the top of a small hill leading down to the ditch in front of our house which would be a major pain to mow. We have been living here 24 years and they were established when we moved in.

The beds are huge - at least 10' x 8' or something around there. Large enough it would be hard to move around in the middle of it. The lilies are just starting to bloom but the stupid bindweed was so thick before I pulled it off that hardly any of the lilies are blooming.

Guess I'll have to be satisfied in just painting the bindweed vines before the lilies get too thick next spring and then around the edges of the bed after everything comes up.