It's not only in your end, there are some performance issues when there are many branches being drawn.
all the tree is being drawn in every frame to get this effect that everythings grows with each iteration and that is something that needs to be redesigned, I will most likely rewrite 90% of the code to make it better in every aspect, performance included.
I will take that suggestion for the full version of the game, giving the player the ability to design new rules for the trees to grow. thanks ;)