Tried with bonemeal and a single redwood sapling. Still waiting on the results from natural growth. And waiting...and waiting...

i'm going to take another look at this at some point this week there should be a way to fix redwoods without breaking worlds.

Would have been fixed by #185

Since this is from 2015, and redwood trees are not the same in 1.16, I am going to be closing this issue.

@progwml6 maybe it still worth merging above mentioned PR in 1.7.10? Most modders are gonna stay on 1.7.10 and skip 1.8. And it might worth to have clean Natura build for 1.7.10 too.
Perhaps, you can warn users that this update will break they're worlds and they shouldn't update unless they are starting a new world. That will solve compatibility question.