Minecraft wiki entry for Tree_farming, associated text: Using the same spacing as a birch farm, one can grow individual jungle tree saplings as small jungle trees. Without fortune enchantments, a single tree would not produce enough saplings to replace itself. A 3×3 grid of trees growing will usually produce enough saplings to replace itself in the long term, and occasionally produces 1-2 excess saplings. After 6-7 real life hours of hovering over the farm, cutting down, and replacing trees as they grow, a profit of about 10-20 saplings can be accumulated this way. A starting supply of 9 planted saplings and 18 back stock for the eventual stretch of losses is necessary to keep the initial tree grid planted at all times. After enough iterations, the ultimate result is a profit in jungle saplings.