Help with trees modeling please!

Hey guys,when i m making trees in blender using sapling mode after that i export them in unreal engine 4 and when i apply the texture to material for exemple a leaf it texture all tree i mean how can i model it in blender so when i export it i can apply separate textures to leafs and the trunk Please help !

Make sure you assign 2 different materials to the tree and leaves separately in blender before exporting, that way unreal will know that they have different materials.
I hope that helps, I dont know unreal.
Also I recommend trying the improved-sapling-tree-generator (full disclosure, I wrote it)