What did TruGreen just put in our lawn (Chicago)

Someone from TruGreen showed up, got on their riding machine, spread something in our lawn, and left. I have no idea what they used because we don’t have service with them. Tried calling customer service but they were no help.

I was preparing to put some Scott’s Weed & Feed in the lawn today but I’m now not sure if it will interfere with whatever they used? Is this worth worrying about or can I just spread the Scott’s?