Sunflower

Sunflowers are large plants able to stop the Corruption from spreading in Pre-Hardmode. They act as background objects like furniture and are obtained by breaking them with a pickaxe. They are also sold by the Dryad. Sunflowers are not able to stop the Hallow.

Sunflowers can only be placed on grass and hallowed grass above ground. Placing them on corrupt grass or dirt will not work. Sunflowers are 2 blocks wide and 4 blocks tall. They cannot be planted in a plant pot. They also have the ability to spawn more sunflowers in a small area, but the chance is very low. No background walls may be present when the sunflower is planted, however walls may be placed behind the sunflower afterward.

Placed Sunflowers contribute to decreasing the unseen total that causes NPCs to reject housing due to the presence of Corruption or Crimson. If placed in large enough quantities, they will offset the influence of nearby converted blocks, and in this way NPCs can be made to tolerate living in a tainted area.