Array modifier with particle system?

I am working on a minecraft like grass block with hair particles as the grass. I added an array modifier to create the ground, but the grass is not applied correctly. The particles get applied randomly across the array like it is a single object. I want the particles to be treated like they are on individual objects with the same pattern as a single instance of the block.

I did it a little bit different than you were describing. I took a cube and put hair on it. Then I used it as the particle of a particle system.
Hopefully that makes sense.