Craft special saplings using 8 of any normal sapling around a piece of bonemeal. These saplings that will grow larger variants of that type of tree.

There is also a recipe which uses 8 command blocks around a piece of bonemeal to create the Forest Mother (shown below). This tree's growth will cause a large lag spike, at least on my laptop.

Remember that if you are working with dark oak saplings you have to plant in 4's! This applies to the forest mother as well.





Enjoy the forest, feedback appreciated.