A small guide on how to find a boss Planter (Plant) in Terraria.
How to find Planter in Terraria
In order to summon Planter, you need to kill all three mechanical bosses. Then go down into the underground jungle, find there Bud planters (pink glowing flower) and break it with a pickaxe or drill.
By the way, if you don't know where to look for the underground jungle, then they are located under the terrestrial jungle biome. To be more precise, you have to descend 400 feet (120 meters) below the sea.
