How do I adjust the distance at which foliage is loaded?

I have a map that consists of a large amount of grass and gravel foliage.
Its really started to affect my frame rate. Im running a gtx 770 with 12 gigs of ram. So I feel like I shoulsnt have such trouble. Its loading the foliage on the entire map. Is there a way to adjust the distance somehow?? Any help would be great.
Thanks!!

Take a look at this tutorial

You just have to use the culling. With that method the meshes will be rendered in clusters and they will disappear when you are in a certain distance. You can find the culling under the instance settings in the foliage tool.