I read once a few years ago there is a way to deter the weeds from coming back in the spring. I printed the method and filed it away and would have to search for it at this point, but what it entailed was two different spreading applications of natural substances about 2 weeks to a month apart when rain would not be imminent. Like first layer in late January or early February and second layer following. All I can remember at this point is that one of the applications had corn meal in the mixture. Supposedly what this does is suffocate or smother out the seeds from germinating that were dropped into the ground from last years weed crop. I have seen a mixture in bags at Lowe's that has the corn meal for the lawn. Anyone familiar with this?