Question
When is the best time to apply lawn grub control in south east MI, 48044. The package indicates a large window of application time, but some nurseries state that the time frame is too broad. Is there an ideal time to apply these products?  

Answer
I would think before the adults come out of the ground.
I don't have to deal with them. I am on an all organic program, and have a healthy herd of lawn critters, toads, lizaeds, and grass snakes. They keep my lawn free of bad bugs better than all the chemical treatments I ever tried.
I don't know what your climate is there.
If you can see grubs now, I would treat now. I think it is better to treat when they are in the larvae stage, before they mature and lay eggs.
Your best source of credible information on this, for your area, would be a local nurseryman, or your County Aggricultural Extension agent.
Charlotte