Vinegar works or boiling water but then you will kill the good things growing around it too. If you have individual weeds you want to kill, the best thing to do is take one of those sponge paint brushes (preferably a small one) and dip it in Roundup and "paint" the leaves of the weed. It takes it down to the root and does not affect the grass around it. It is time consuming but it works.
By
05/09/2010
I've used bleach, but I don't like to because I doubt it's safe for the environment.