making undergrowth longer??

[-=25ID=-Marine]

how do i make the grass in the undergrowth longer then it already is?

also i have a problem on the edge of my map these huge mountians are appearing on the edges without me making them, i cant see them in editor why is it doing that

thanks for all the help!

[CrimsonBlaze]

it would be due to the heightmaps. go to Render -> Surrounding Terrain -> Toggle All to view them.