So, I'm trying establish english ivy/japanese crawler in our driveway border that's elevated and can't be mowed. It's taking fine, but there is a 2x2 spot that ivy or the crawler won't grow in. I dug it up before and removed a football size stone, filled it with soil and replanted. But it stll wont grow, the japanese crawler is now struggling, where is fine in the rest of the plot. Have I found the portal to an evil underworld?