Unfortunately, you can't have weed killing without the yellowing. The grass around those areas will recover within a few weeks. This is why we emphasize getting on a consistent program to prevent weeds from popping up. In the rare case one does come up, we will treat it, the grass around the weed will turn yellow for a brief period and will then recover. *Most lawns we have had for years won't have this problem often because they rarely have weeds.