In The Plant Factory, realistic looking trees can be created with a few nodes and appropriate parameters. Megascans maps add realism..
Megascan maps are very detailed and include some leaf textures. This tutorial shows how to adapt them to create plants in the Plant Factory..
Detailed tree models are typically more than 20K polygons. Even with modern software, they can be heavy to load for busy scene. Here is a simple process to create a 6000 polygon tree with The Plant Factory..