Help with grass

[Pandachoko]

Okay this picture below is actually classified about Custom Story, but I need your help. So I am making this huge outside area. but I need your help

You see the only thing I need in order to complete my custom story, what I mean by that. That is when I am 90% done ( I need the scripting)

I need grass all over the place, and the fastest way I found so far is to place a couple of grass models and when I have enough to make a area, I mark them all and then duplicate the grass models I choose, but I was wondering is there another way, I would like to know(you know to speed up the progress? Thank you for the taking your time. please let me know!