Roofed Oak Sapling

Roofed Oak Saplings only grow when arranged in a 2x2 arrangement, same as large Jungle Trees. That can't grow from a single sapling.

Although I will say this will likely confuse a great deal of players new to the tree. I'm curious if there would be a way to convey this to the player, so they don't plant tons of these one at a time and become confused or frustrated when nothing grows from them, thinking them broken.