Minecraft wiki entry for Huge_fungus_generation, associated text: Similarly, if bonemeal is placed inside of a dispenser, and then that dispenser is pointing into a fungus plant on its respective nylium block, then there will also be a 40% chance of it growing per attempt. Dispensers can be used to automatically grow the fungus plant, and up to 5 can surround a fungus plant, allowing for fungi to grow at 5hz on average.