Well, it's not magic. There's a reason why it states a required amount of irrigation/water needs to be applied POST application.

 

Yeah if you didn’t water it in with in 2 weeks of applying that is where you failed at. Lawns like consistency with feeding, watering and mowing.

 

The weeds are breaking through in my opinion for two reasons. 1. You should have applied in late August to early September for Spring weeds. What you applied in Jan will help for summer weeds not spring weeds. 2. You need to water in at least 1/2 inch within a week or so.

 

I agree with the above, you most likely applied too late. Those winter weeds were already in the germination stage. Add in, that mother nature may not have provided you with an adequate amount of rain.

 

It sounds like you might be seeing winter weeds, which would indicate you missed the window for your prodiamine treatment in Sept/Oct/Nov (depending on location). Your application in Jan/Feb/March protects against summer weeds. In both applications, follow the label and definitely ensure it's been watered in.

I do split applications for winter and summer weeds just to cover my butt because the weather is unpredictable.

Either way, don't worry about it. Once you fertilizer and water it this summer it will choke out most of those weeds and you can just work on better timing for the preemergent applications this fall.