Ahhh, I see why. The seed bounces!
You have it set so that it grows a sapling when it collides with the ground; it just so happens that it hits the ground and bounces twice, resulting in THREE saplings instead of one.
SECOND edit: Wait a minute, I didn't even look at that "Next" variable. That does the job I just described before... Oh, the problem is that you should add 1 to Next BEFORE the "Wait 1 second" action. Then it works.
Edit: I gotta say, I'm curious about where you're going with this project. Mind throwing us a few details? SullyTheStrange2012-08-09 05:43:45