It's funny that its more accurate to think that trees materialize out of thin air, rather than grow out of the ground. Trees are about half carbon and half oxygen. All of the carbon and some of the oxygen comes from C02, which comes from the air. So you plant a seed, which puts up a few leaves. Then over hundreds of years the rest of the tree gradually (with the help of sunlight and water/minerals from the ground) condenses out of the air into an inexplicably solid and complex structure. Here is Feynman explaining it.