Is there a product that will kill grass and weeds without killing blooming flowers?

In my flower garden the weeds and grass have gotten out of control. Is there a product out there that I can use to kill those weeds and grasses without killing my flowers and plants?Is there a product that will kill grass and weeds without killing blooming flowers?
Unfortunately not . Life would be a lot easier if you could.I would use a grass strimmer to whack the weeds down to ground level , then you would have a chance to use weedkiller without damaging the plants.If thats not practical you could always use a hoe.Is there a product that will kill grass and weeds without killing blooming flowers?
Preen will not kill the grass and weeds, but will keep the seed from germinating AFTER you remove the existing plants, root and all.