Need Advice: New Lawn Being Seeded in August

Our new home is being constructed in northern Indiana in sandy soil. The way contractor scheduling worked out, the final grade on the land has been done, sprinklers going in soon, but it will be several weeks before it can be seeded. Of course weeds are already growing. Concerned about there being too many weeds when it's finally seeded and if the new seed in summer conditions has any real chance.

I know it sounds crazy, but should I attempt to de-weed the soil right before seeding and if so what is the best way? It's about a half acre. I know I can't spray anything on the weeds until after 4-5 mows.

Just don't want to have to start the whole lawn over next year.

Thanks!

I'd use Roundup to kill all the vegetation, you can plant after 3 days of use. Depending on how extensive the weeds are, you might need two applications, about a week apart. I'd also hold off seeding until the sprinklers are ready for use. You're going to need to water lightly at least twice a day for the first few weeks, depending on grass type. I'd also speak with the contractor about seed. Many use a cheap variety with lots of annual blue/rye. Grows quickly but dies in the winter. If it were my lawn, I'd talk to a local sod farm that sells seed. They can be helpful in determining the right mix for your climate. I'd also test the soil before planting. Down here in SC we have red clay, usually low pH. You can get a soil test at your local ag agency. Don't waste your money on the self test kits, not reliable. Hope this helps.

Thanks georeedy.