Plantera is a major Hardmode progression boss that becomes available after the mechanical-boss stage. Defeating it opens several important late-game systems, so it is one of Terraria's most meaningful progression checkpoints.
Before you search for a bulb
Make sure your weapon, armor, accessories and mobility already feel comfortable against Hardmode enemies. The fight is much easier when the arena and loadout are prepared before the summon.
Arena preparation
- Clear enough Jungle space to move in more than one direction.
- Build platforms or loops that support continuous movement.
- Bring healing and mobility that work in tight terrain.
- Use a loadout already tested against Hardmode bosses.
Fight approach
Keep movement predictable and avoid getting trapped against walls. Reliable damage uptime is usually more valuable than risky burst attempts that force you into bad positioning.
After Plantera
Post-Plantera progression opens stronger enemies, areas and later bosses. Use the Hardmode hub to decide whether your next priority is the Jungle Temple, equipment upgrades or late-game events.
Source: Official Terraria Wiki.