Minecraft wiki entry for Shelters, associated text: Eventually, you will use up all the trees in your immediate surroundings, so you will want to replant them with saplings. Keep it well lit, both to keep away mobs and speed up the growth of trees. Birch is recommended, because it grows fastest, but oak and jungle trees are also a good choice, due to their apples and immense size respectively. It is difficult to build an indoors or underground tree farm that will supply your wood needs, unless you use bone meal or keep it well lit. Create a room that is bigger than trees.