With my first sapling in hand, I carefully carved out a room deep in the netherrack, and another room above it where I cast a concrete floor in case the tree started sending tendrils up through the soft netherrack. I used a soul urn on it, and it swelled to adulthood. I watched as it slowly began to bush out and soon saw it encounter the netherrack walls of the room and... stop. I guessed the rumour about it growing through netherrack was false.
I pruned it back to the central trunk, hoping that it would start growing again once it had enough space, but it just sat there, sad and stark. I planted another sapling in it's place, then returned to the internet to find out more about the mechanics of blood tree growth. Armed with the new information, I decided I could risk planting one in the open, as long as I placed it in the upper levels of the nether, and away from any soul sand deposits. This tree grew up and out until it hit the ceiling of the cavern about 15 blocks above it, and continued to spread out horizontally a little, but I was disappointed with how well-behaved it was for a tree infused with the tortured souls of the damned.
I decided to take it to the next level and planted one right at the bottom of the same cavern, and even laid a small bed of soul sand for saplings to fall on. It grew, and grew, and grew, and obstructed my nether rail with a few leaf blocks, and caught fire when it grew into lava falls, but ultimately the growth slowed down as it encountered the ceiling, and the fires carved out large voids in it's interior which so far show no signs of being filled by fresh growth. It didn't destroy anything or turn the nether into a solid mass of wood and leaves, and if anything, it helps me by providing my nether rail with some extra cover from ghasts.
Does anyone have any experiences of blood wood trees actually being problematic? I was hoping they'd be a lot more invasive and difficult to control than they turned out to be, and I'm not sure why people made such a fuss over them.
