I applied a 16-4-8 Fertilizer to a clients lawn per his request. He has now asked why there are weeds (Minor and very few, yet some) popping up in his yard, and has stated that he requested a 16-4-8 weed & feed fertilizer be used. My question is what can I do to correct this. Can I apply a weed & feed now? It's been about 3 weeks since the application. Any ideas would be helpful. Thank you in advance for all your help.