Issues when making a Landscape

I started poking around Unreal Engine 4 a few days ago and so far everything seems to easy and intuitive to work with. However I am having serious issues with building and editing a landscape.

First it seems you can’t just paint with any material you want? You need to create a specific material with the many textures you want for your landscape? At least that’s what I got from the tutorials I saw. I don’t really understand the reasoning behind it but I’m able to manage it.

The issue I’m having and that I really can’t figure it out for the life of me is that the Landscape appears tiled. I used the same material on a Static Mesh and it works just fine, like it’s shown on the left side of the photo, but on the Landscape it gets extremely tiled.

What could cause this? Is there something I can do to make it look better?

Any help would be greatly appreciated.