Can i animate the strenght on the displacement modifier ?

It seems like not , so how do i make a mountain grow ?

Yes you can. Create Object and Material. Material IPO Window. Create IPO for Displ. channel.

If you want to use the displacement Modifier and not a displacement texture like kkrawal suggested, you can try adding a Texture IPO to control the Contrast of the texture you are using for the displacement. I did a quick test and found that setting the contrast to 0 (on a grey scale image) works to have no displacement (Basically makes the texture all grey). You can then use an IPO to raise the Contrast of the texture over time and the displacement will grow. One caveat to this is that the change does not appear in the 3D view unless you tab in and out of Object mode. However, the changes do effect rendering automatically.

Hey, that’s great. I was getting horrible results using the displacement IPO as I have a edge split modifier added too.