I cant say for sure but from what I have heard you shouldnt use saplings for bows. They dont have the same qualities as a mature wood and are too flexible with too much memory. Ive heard they can get stuck in the bent position. The literature I have found says you shouldnt use anything less than a 4 inch diameter tree. Im not saying dont do it but, personally, I would be considering this an experimental bow build and I would definitley heat temper. Good luck and let us know!!!