I can't give up, I'm really tenacious (if that's the right word). I want it perfect (within my abilities), and it is a commission, so it should be good.
And Frank, you're right, but these guys made their homes from the dirt they live on. But I might change it slightly, or give the bottom part a more grubby color (by distribution shader+PF). Or grow some weed/grass at the wall base. They probably weren't 'perfect gardeners', these Roman farmers.