Blending Textures together?

Ok so I have a grass texture and a rock texture but want them to blend together at certain points, so that you will see rock through the grass and stuff like that. How would you go about do that? I thought I saw something like that for Yo Frankie using alpha or something, but I can’t find it again.

Thanks.

You can use a stencil texture either in between two texture channels in your material or you can use the material nodes. There are several tutorials on this topic that I have seen here and on BlenderNation.

Ok thanks.