Best way to spawn lots of actors at beginplay?

I’m trying to populate my level with trees, rocks, bushes, grass and other misc details.

Using instanced static meshes for them all is what I’m trying to do but for some reason nothing has their collisions and so my pawns can walk right through them. And then everything is overlapping too. So trees will just spawn inside each other or in a big pile.

And if I do use instanced static meshes the actors lack any blueprint functionality, but having 1000s of actors on screen kills my fps.

If anyone knows a way to spawn lots of meshes at beginplay so they don’t overlap, keep their collisions and bp functionality that would be awesome.

This might help Unreal engine 4.8 procedural foliage spawner tutorial - YouTube