@gaoron: A thousand petals is literally the amount it takes to form a sword of Ichigo's size. Which means that no matter how Ichigo swings his sword is bound to collide with at least a thousand of them. The problem here is that Ichigo's sword will not magically stop each time it hits a thousand petals. Instead his swing will continue moving and hit another thousand then another thousand etc In this way, by the time Ichigo finishes a full swinng he would have already blown away tens if not hundreds of thousands of petals.
1. By past hype Ichigo. By feats and several statements Naruto