Thanks a lot!
The scene is very simple. It's just ground with a road in centre. And a few trees that I have builded in GrowFX. I use Forest pack Pro to scatter trees grass and dead leaves on the ground. For lighting I have used spherical HDRI from VizPeople.
First trick is a Vertex Color map, that used to make diversity of leaf colors. It's great and very useful feature of GrowFX.
Second trick is a tree models. There are no any good trees models in any paks (like Evermotion). So it's only one way - you should make it by yourself. And GrowFX is excellent tool for this.
And finally is good materials. On first look material for vegetation is not so difficult. But here is all about balance between Diffuse, Translucence and Reflection. I spent A LOT OF TIME by testing it. And now you see the result.
In attachments you can see a few screenshots with my scene and trees and base material for leaves. Enjoy :)
PS. There is almost no postwork on those images. Only a little bit color correction, vignette and chromatic aberration.