Stop The Spreading?

[Natneg]

I recently just beat the Wall Of Flesh and upon reaching the surface I noticed the corruption was a lot closer than when I left to the underworld, I tried purification powder but it just came back and its almost to my house. Is there any way to contain it or get it to stop spreading?

[Space Attorney]

I remember reading that sunflowers were supposed to stop the spreading, but I don't think it's true anymore. Your best bet right now is to replace the ground around your house with any block that can't get corrupted. Later on, you'll be able to buy the Clentaminator to clean up corruption really fast. I've also read that once you beat Plantera the spreading is slowed down (although it never seemed like it to me).

[Gysahl Greens]

The "evil" (corruption and/or crimson) have started to spread and they will infect any infect-able blocks, which are stone, sand, ice, and dirt blocks with grass. They will also turn mud into dirt and infect the grass that grows on it, but the process is slow. The infection can only reach up to 3 blocks away, even past immune blocks like clay or stone slab. So you can dig out a 4 block wide shaft between the corruption and cover up the side with corruption with immune blocks to seal it in.

Remember that corrupt and crimson grass in open areas can grow thorny bushes that grow up to 4 blocks away from the grass and will infect vulnerable blocks like usual. Covering corrupt and crimson grass with immune blocks will prevent the thorny bushes from growing.

[Natneg]

Which blocks are non-corruptible?

[Bomb Bloke]

Originally posted by Space Attorney:

I remember reading that sunflowers were supposed to stop the spreading, but I don't think it's true anymore.

It certainly stops being true once you hit hardmode.

Originally posted by Natneg:

Which blocks are non-corruptible?

Pretty much anything that isn't "natural". Placed wood, stone bricks (as opposed to blocks), etc.

Fortunately, you don't need to worry about background walls.

[HughManatee]

Snow is immune to corruption.