I used a drill to drill holes around a diseased maple to feed it iron supplement at root level. I could have sprayed the supplement onto the lawn, but it was clear that I was applying it where the roots would absorb it more quickly. I know this because I hit the roots on several holes. The trick to using this auger is to use short pulls and quickly remove the auger completely from the hole before it gets stuck in the ground. If it gets blocked, it will sharply twist your hand on the drill.