SpeedTree - SpeedTree is a powerful toolkit used to create 3D vegetation for video games, films, and animations.
Arbaro - Arbaro is an implementation of the tree generating algorithm described in Jason Weber & Joseph...
Tree Studio - Easy 2D Tree Creation
ngPlant - ngPlant is a plant modeling software package.
Treeit - Can create awesome 3d tree models and export to obj file format.
Plant Factory - PlantFactory is packed with amazing features that deliver unsurpassed realism and performance. An essential tool for any VFX pipeline, PlantFactory will have you creating stunning digital art in a flash!