Procedural trees can't be baked?

Hey, I have created a bunch of procedural trees in my current scene. They seem to bake fine, the shadows are baked.

In the viewport, if I turn OFF lighting, they have a soft look, and are lit by the baked lighting. if I turn ON lighting, they are black. All lights are set to 'baked only'

When the game plays, all trees are black..

Can procedural trees not be baked??

ps. they are all set to static.

 

Fixed

 

When you fix, it's nice if you say what was the problem and how you solved it

 

haha I didn't get any replies.
I just ended up exporting the Unity trees and importing them.