Cycles - Fading out material

Hello again …

my problem is a material which I want to fade out.
First shader is diffuse shader and second I used trasparency … but I noticed it doesn’t work that way.

Do you have an idea how to use gradient from a visible color material to invisible one ?

Below a screenshot with my underdeveloped idea …

  1. Be sure you have actually unwrapped the plane. I reset the rotation and scale with CTRL-A for good measure, but it doesn’t look like that made any difference.

  2. I got mine to work with your setup by setting z rotation to -90 deg, and swapping the shaders on the mix node inputs.

  3. Experiment : ) Changing the y scale is what changes the gradient spanning distance. Go figure. Not what I would have guessed.

Nice and easy.
Thank you a lot !