Hello Renee,

The optimal time to apply crabgrass pre-emergent herbicide in Oakland county is right now. Your area is projected to be past optimal by this weekend. Please see https://gddtracker.msu.edu/, enter your zip code and choose Crabgrass PRE in the right panel. The green band is the proper timing to apply a pre-emergent herbicide.

Generally, you need to wait 3-4 months after applying a pre-emergent before successfully seeding. So, you have three choices: Overseed and do not apply pre-emergent, apply pre-emergent and seed in the fall or find a pre-emergent herbicide FOR SEEDING and you can seed after applying the product.

There are currently crabgrass pre-emergent herbicides on the market that are formulated to be applied at or before seeding. One of the active ingredients in these products is mesotrione.

I do not understand your statement that “big box preemergents are awful”. The product available in big box retailers contains the active ingredients that MSU and MSU Extension recommend. What are you basing your statement on? If you are basing it on reviews or social media, be careful that the product’s effectiveness is dependent on reading and following the label instructions. Quite often, poor performance is due to incorrect application. Here is information on pre-emergnet herbicides: https://www.canr.msu.edu/news/timing_crabgrass_pre_emergence_applications

https://www.extension.iastate.edu/news/yard-and-garden-pre-emergence-crabgrass-control

Corn Gluten Meal is an effective organic solution for crabgrass prevention. https://www.extension.iastate.edu/news/2005/mar/mar0522.htm

There would still be a significant wait until grass seeding would be successful.

Hope this helps.