This is the small forest scene from my most recent tutorial which you can watch below!
We use Arbaro to get the two plant models in this scene...
Hope this helps you!
How can I use this on Unreal Engine 4?
There are a variety of tutorials on the web for that. You will have to export it in a format recognized by both programs. The materials do not carry over, but most other does.
That is true, the objects can be exported to the engine, however materials are a different story. Not sure myself if it is possible or not :)