An experiment with adding ivy on top of an earlier stone wall material I made (https://www.materialmaker.org/material?id=1097).

I'm pretty new to blending height maps, so I'm not sure if this is ideal. I'm guessing that in a perfect world, I would create a material for the branches/leaves of the ivy (distinct from the main roots of the ivy) with an alpha mask, and then placing the branches/leaves on the ivy much like how game-ready trees are designed. This way, the underlying geometry looks a bit cleaner.

That said, I did try my best with making it all one material. The compromise was to have only the thicker portion of the ivy roots have the height, while the thin branches and leaves basically got no additional height and were detailed by the normal map only; this prevented odd looking displacement of the small leaves on the bricks.

If there is a better way to achieve the desired effect, please message me :)