How can I kill nutgrass and other stubborn grass weeds with bulbs that are growing between pavers? I've tried Yates rapid weedkiller but it just killed the leaves- there's still new growth and when I tried to pull them out they just break off at the stem. The gaps between the pavers are too narrow to pull them out. I did manage to lift a few pavers and dig out some bulbs but there are tons of them and I don't want to lift and loosen all my pavers. Is there any other way to do it?