When should I thatch after hydroseeding?

Moved into our house a year ago and replaced our whole front lawn. Hydroseeded June 1st, and the grass grew well but so did the weeds.

We are going to spray a selective weed killer 3 months after hydroseed, Sept 1st. But I imagine the dead weeds are not going to magically disappear.

When should I thatch after killing the weeds? Let them sit until April to give the grass better roots?


I’m not an expert when it comes to this, but I’d wait. Dethatching is aggressive!