Mushroom Grass Seeds

Mushroom Grass Seeds are a type of Seed that has a chance to drop from harvesting Glowing Mushrooms, and can be used to grow your own Glowing Mushroom farm.

Requirements
Mushroom Grass Seeds must be planted on Mud Blocks underground (below 0ft depth) in order to grow Glowing Mushrooms. Once the seeds have been planted in a suitable location, the blue grass from the seeds will spread. Mushroom grass does not require water.

Grass
Mushroom Grass spreads much slower than ordinary Grass or Corruption, at a speed comparable to Jungle Grass, which is only 3-5 tiles per day for each contiguous section of mud blocks. The blue grass, as well as the mushrooms that grow on it, give off a nice level of light; less than a torch but enough to see clearly (when placed against a solid wall, the light will penetrate 2 solid blocks).

Also note that the blue grass seems to spread faster when it isn't lit up by any other light source but its own.

Giant mushrooms
Giant glowing mushrooms can also spawn in player-grown Glowing Mushroom farms; however the mud blocks must then be placed far enough below ground level ( at least 16) that the tops of the eventual trees will still be below ground level. They also require the same amount of vertical clearance as trees: 15 tiles.

The requirements for trees means less mushroom yield, since mud strips can't be placed densely on top of each other with just 1 tile of clearance as usual. Nevertheless, trees are aesthetically pleasing, have a high chance of dropping more Mushroom Grass Seeds, as well as multiple glowing mushrooms each, so they may be worth the trouble for some players. Giant glowing mushroom must be chopped down with an Axe.