Due to it being active for a year and "not impacting nearby vegetation" as per your promotions, we are considering Sahara herbicide for bare ground control along a grass edge. So as to prevent movement beyond that strip, we are considering removing a six inch wide strip of soil alongside a grass edge, spray that strip, and pull the soil back over. We want the deepest depth that will still be effective. How deep should that soil removal be: 1/2 inch to 1 inch, 1 and 1/2 inches to 2 inches, of 2 and 1/2 inches to 3 inches? Will grass roots reach out to that strip and kill the edge grass? If so, how far away from that grass edge should we spray to be safe? Assuming a mixture of grasses, some with rhizome roots, will some reach into that bare ground and die, others not reach out, and those that did not die fill in the space of those that did die? We are planning a thorough, several spot, test first so we should not get in trouble. But we thought we should ask your advice first.