I'm not a landscaper, but pretty much handle all the lawn care for my family's home. I used a Scotts spreader to spread a home depot brand weed & feed chemical fertilizer (Vigoro). Never had an issue with these brands before, but a few days after application and rainfall, I noticed yellow grass in certain areas. Not sure how it happened since I spread it consistently. Is it the soil quality? Maybe over-spill from the spreader? (I might add that these are weaker spots of the lawn) I flushed the affected spots with 20 minutes of watering over a few days. Its been about 2 weeks of rain and its still yellow, not brown. Will this require new soil? Any thoughts or advice would be appreciated, it doesn't look bad from the road, but up close is awful. Thanks!