NOTE: YOU NEED LEVEL THREE DENDROLOGY.

You don't need all the wind flutes to meditate. Place a villager in the middle of the flutes and he will sit down and meditate. Note that if anyone goes near the villager, he will be distracted. Wait until the villager stands up and has yellow dots around his head, then drag him into the pond (make sure it is soapy). He will then have white sparkles around him as well. Drag him to the tree and he will bring a beetle to the fire and the tree will be purified.