I had what was an almost weed-free lawn next to a beautiful wildflower garden. My problem - wildflower seeds continue to drift into my lawn. Should I give up on having both? Or, should I plan on spraying my lawn with Weed-b-gone on a regular basis to kill the weeds (wildflowers) in the lawn.

I especially have problems with Yarrow.

Is there a safer and/or more effective weed killer than Ortho's Weed-b-gone Max for control of Yarrow?

Thanks.