bushes with the terrain editor

hello, I'd like to be able to easily place bushes via the terrain editor with the tree or detail brush, but the soft ambient occlusion shader doesn't seem to be completely accurate to PBL, such as when a shadow is cast across the plant. I used this guide here:
http://docs.unity3d.com/Manual/terrain-Trees.html

My bushes are all prefab FBX'es, and I don't need them to move in the wind, but the placement would help a lot. If there is a better asset for unity 5 for painting on meshes that people recommend please link, thanks

 

https://www.assetstore.unity3d.com/en/#!/content/14954
I haven't used it but sounds like what your looking for.

 

thanks this looks good