Answer: Without knowing what weed you have it is difficult to be specific, but here are some ideas. One option is to pull the weeds by hand and then mulch the plants with 4-6 sheets of newspaper covered by a leaves or pine needles.
Another option is to use a "wiper" type applicator to apply glyphosate (Roundup is one brand name) to the weeds without getting it on the junipers. This herbicide will move down into the roots of the weed (including the grassy weeds) and kill the plant. Be careful not to get it on your junipers.
I hope this helps. Good luck in the war of the weeds!
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