In zone 7, an existing yard with crabgrass and bremuda (not desired in this area) , I need to kill everything and reseed. There are a few area that I need to regrade so this part is simple, but using a hydroseeder how would you guys proceed. I need to use a turf-type fescue. Conventionaly I would spray with non-selective herbicide(gyosophate) almost LOL. Then respray after 14 days, then tear-up the lawn and prep the seed-bed and add ammendments and seed, covering with a blanket of straw. Is there a way to core areate and spray then follow with hydroseeding, without removing the existing dead grass? I have heard about seeding behind round-up or possibly putting round-up in the tank (hydroseeder). Also Drive has been mentioned, I assume this is a pre-emergent. Any experience with this. If this is proven I can try a test plot, my parents are after me to re-do their yard, (free of course, but they paid for it years ago, LOL) This would make a good experiment, but I don't want to do something ridiculous without some good idea of the results. BTW I haven't bought the hydroseeder yet, but will own one soon, just haven't picked the model or previous owner. But it will be mechanical agitation.