Why God needs leaves

We're driving down the street when Mwende sees a couple of trees that don't have leaves on them. She exclaims, "Oh no Mama! Those trees are dead! They don't have any leaves!" "Oh no..." I say. She says, "Does that make God sad?" "I'll bet it does, God likes leaves." I respond. She thinks for a moment and then says, "I know why God needs leaves!" "Why?" I ask. "God needs leaves to make celery!"