Minecraft wiki entry for Nylium, associated text: Similar to grass blocks, the player can apply bone meal to nylium. This nylium, along with nearby nylium, generate vegetation that occurs in their native biome (crimson nylium generates mostly crimson forest vegetation and warped nylium generates mostly warped forest vegetation), and just like in the native biomes, the opposite type of fungi occassionally generates. The vegetation is generated in a 5x5 area, centered on the nylium block on which bone meal is used.