I have a potential customer with a bare lawn. He has tried to grow virtually every variety of grass and has sodded the lawn twice with St. Augustine. He has a large Sweetgum tree with lots of roots and lots of shade. The ground has a thin layer of clover and dollar weed, but is primarily dirt and roots. I feel like we could get some business from him if I had a viable solution for him to grow some grass. He has an in-ground irrigation system, but watering doesn't seem to help. Any ideas?