The best "weed" control I have found for use around any flower is my hands. Any broad leaf weed control you use will also adversly affect the flowers if any of gets on the plants foliage. All of my planting beds are well mulched and I seldom see any "weeds" and those I do see are easily removed by hand.

I glare at my weeds until I burn them up with my thoughts.

A classic way to rid your lawn/garden of broadleaf weeds is to mow maple leaves into the lawn and garden in the fall. Over time, broadleaf weeds decline. Something in maple leaves acts like a natural herbicide.