@dhinge: "Turn 3 you play Maralen of the Mornsong, then next turn you grab Colfenor's Plans from your library and toss it out. Next turn grab Sapling of Colfenor, then toss it out or Leaf-Crowned Elder."

I'm not sure if I'm reading the cards wrong, but Maralen Monroe says, "At the beginning of each player's draw step..." and Colfenor's Plans forces you to skip your draw step. This means that you're hoping to exile or already have Sapling of Colfenor / Leaf-Crowned Elder already in your hand when you cast the Plans. It's a good attempt, but it won't work how you're thinking.