Hey there,
my Idea is quite simple. Is it possible to add an option that looks a bit like that:

gameplay:
  customTreeOnBonemealOnly: false

If this option is true than custom trees only grow if a player uses bonemeal on them.
I really don't like the default trees but some player really do. Adding this option would give everyone the opportunity to have those kind of trees that players prefer.

How to:
simply add something like this:

onStructureGrowEvent(StructureGrowEvent event){
  // Your code ..
  if (customTreeOnBonemealOnly)
    if(event.isFromBonemeal())
      return;
  // Your code ..
}

This would help me a lot :) Thank you for your plugin.

Your plugin is great, but unfortunately it turns off the default trees, which are easier to cut down.