My 2c after a lot of thought and reading here and elsewhere is that it simply isn't green really to plant a lawn. You can take care of the lawn using green principles, and once you learn the ins and outs can do it very well. But planting the initial lawn -- versus say more naturally dominant weeds or groundcover in and of itself is a choice to be less green than you could be So imo, suck it up, be green as soon as it comes in but until then use best practices followed by the pros here to get the lawn installed as quickly as possible. Roundup, wait, till it all, round up again, wait, then plant is what I've learned. Then, if you choose, never again use chemicals that aren't natural.