Containing in Hardmode

[吹雪 - FrostSpark]

I read some guides for containing the hallow and corruption/crimson in the hardmode and I always read that you have to fill out the 3 to 5 block wide hellevators with wood or some kind of block that won't get transformed. But why should I fill in blocks in them? As far as I know hallow and corruption/crimson can't spread over 3 blocks regardless of whether there are blocks (non corruptable) or not.

[Play For Fun]

I'm pre-hardmode so i might be wrong.

From what i've read, guides didn't state to fill them with wood. It means for horizontal spaces, line the sides with wood to prevent vines from growing as vines do spread corruption and vines can grow to very long.

[Daisu]

I haven't heard anyone saying that you should fill in blocks, it's better to make a hellevator instead, or plant sunflowers if you don't wanna mine anything, corruption and crimson don't spread on the block below sunflowers, idk about hallow tho, you can try.

[吹雪 - FrostSpark]

In hardmode corruption and crimson aren't stopped by sunflowers anymore... And vines only spawn in jungles don't they?

[BEAR]

Hanging plants can spawn wherever there's dirt or mud. Vines the crafting material are only dropped by man eaters and their cousins in the Jungle Biome. Also, the only way I've efficiently kept the crimson/corruption and hallow at bay is using the clentaminator.

[吹雪 - FrostSpark]

Ah... you mean the hanging plants. I will try to dig a 4 block wide tunnel below my base and to seed some hallow to the left and right of my jungle. I hope this will do it.

[Torchfire]

Hanging vines and corrupt thorns can't grow through objects such as platforms or rope. Placing those in problematic spots can prevent biome spread.