There appears to be no solution to this puzzle. The two plant creates on the side of the first rock where the star is will extend to kill you if you jump in front of them. You can create a block in front of you, but that is not helpful here. You are blocked from going forward by a mossy rock. Changing form does not give you a different spell. Is there something I am missing? 
Update: I figured out a solution. If you create a block a space and a half before the mossy rock and then create a block underneath the first big rock, you can jump on the second block you create and walk across the obstacles in front of you. Then it's a simple matter of jumping to the top of the second rock and creating enough blocks in other direction to reach the star for this section.