So I created this new worldspace, but the one thing that annoys me is that there is no grass like you would see in the Mojave or Capital Wastelands. So my question is, is there a way to spawn grass on the entire worldspace? Or even just a way to add it to certain regions. I've been researching but can't find any solutions.

Maybe this'll help http://forums.nexusmods.com/index.php?/topic/397828-removing-grass/

Apparently, its the texture that decides where the grass grows.

TRY looking at the assets for The Strip, there's plenty of grass near the Ultra-Luxe, would that texture be up your alley?

If you're looking for something more wild. Look at Vault 22 maybe? Or are you looking for something more brown and frontiersy?