Unity playing around

I've imported my trees into Unity, and fixed the textures - there was a problem with the program recognising the alpha textures I was using in Maya so I recreated my textures as PNGs with transparency and used the defringe tool in Photoshop to get rid of the greyed edges.

My next issue is trying to stop the program from backface culling because my leaves look invisible from beneath. My last 2 tasks are building a basic environment with trees & natural lighting and making a simple VR video of my environment for Google Cardboard view.