Blending two materials with weight paint?

I have two materials set up with seamless textures. (e.g. grass and dirt) Can I use weight paint to blend these two materials together for example making a dirt road in grassy hills?

No. Use vertex colors (vertex paint) instead.

Thanks. I rarely use vertex colors so I didn’t think of that. You can mix materials using nodes even with the internal render. I also found a video tutorial:

Can you copy the vertex paint values to weights?

you can also use UV mapping, which is more accurate than vertex painting. the first link in my signature is a mini-tutorial on this method.

I know you can do it with textures but I need the two separate displacement modifiers to match the change of material so I suppose I must use weight painting?