Plantera's Bulbs are used to summon Plantera, a Hardmode Boss. They are background Hardmode items found naturally placed randomly in the Underground Jungle after all 3 of the Mechanical Bosses have been defeated. They must be destroyed with a Pickaxe, Drill, or block-breaking explosion in order to summon Plantera.
Plantera's Bulbs emit moderate light and appear in the minimap in areas the player has already explored. They spawn one at a time after a delay of about half a day between them, and unless destroyed, several will eventually be present (10-15 in a small world's naturally-generated Underground Jungle). If destroyed, they respawn after the same delay (though not necessarily in the same spot), allowing the player to summon Plantera an infinite number of times.
- Bulbs are very easy to spot, as they emit a faint pink light. They will also be labeled "Plantera's Bulb" if you hover over it on the map screen, where they appear as small pink areas.
- Plantera's Bulbs can spawn in player-produced Underground Jungle areas.
- Bulb placement is partially random, but they do spawn at somewhat regular intervals of roughly 150-300 tiles from each other. The more Underground Jungle a world contains, the more Bulbs will spawn. They do not require Underground Jungle between them, so small areas of Underground Jungle at least 300 tiles away from each other will each eventually spawn Bulbs, as long as each area contains enough Jungle Grass to qualify as an Underground Jungle biome (see image to the right).
- If a bulb is broken after Plantera has already been summoned, a second Plantera will not spawn.
- The bulbs seem to spawn near Life Fruit. If you find a bulb, and haven't yet achieved 500 max health, explore around the area for awhile and you will most likely eventually find one or more Life Fruits.
- If one of the two blocks under the bulb turns in a Chlorophyte Ore block, the bulb will break and Plantera will spawn.