A tree15 inchesin diameter should hold it if it's installed and braced properly.You get a lot of torgue from a two man ladder. Really, it would be better if you had a double tree or two trees close together and wedge the stand into the other tree as you lash it to the one. When you get that puppy all tied down I like to go down and grab the bottom rung or two and pull it out from the tree as far and hard as I can. This leverage really tightens things up. Then bounce on the bottom rungs to drive it into the ground so it can't move in. Sometimes(usually) you got to add a good ratchet strap at the top to hold things in place. Even then, you have a lot of leverage if you get all the way one side or the other.