Trees can be grown underground in Minecraft PE. In fact, underground trees don’t require natural light, water or anything out of the ordinary. What they do require is a single dirt block and both horizontal and vertical space.
Space Required for MCPE Trees to Grow Underground
Vertically, plan on at least 7 blocks above the sapling. The height required can vary based on the type of sapling planted. As far as horizontal room, we have seen trees grown in rooms barely deep and wide to contain them.
Testing Your Room Size
A good way to test and see if your room is large enough is to first plant the sapling in the middle of the room. Next, use bonemeal to encourage the tree to grow. If you’ve used sufficient bonemeal and nothing happens your room isn’t large enough yet.
The photo below shows our test of an oak sapling planted underground. With a bit of bonemeal that sapling quickly grew to be the oak tree in the picture at the top of this page!
Last Updated Oct 15, 2016