Use the Clentaminator with Dark Blue Solution. Note: This requires the Steampunk and Truffle NPCs. Surface Glowing Mushroom Biomes do appear naturally and must be player created. To do this, get Mushroom Grass Seeds that are dropped from Glowing Mushrooms in the Underground Glowing Mushroom Biome. Then, go on to surface (above depth 0) and plant seeds in Mud, and not Dirt. Plant the seeds at every second or third block. Allow it to grow as Grass, and Mushrooms will spread by themselves. After reaching 100 blocks wide, the Glowing Mushroom Biome will become a permanent biome in your world.