Necro posting here. I had the same problem today, and was able to fix it. Just to be crystal: the hardwood stump I am talking about is on the Four Corners Farm, in the NW quadrant. Inside that quadrant, it is the node in the SW corner of that quadrant. There was a pine tree and some weeds growing there, but no hardwood stump. I chopped down the tree cleared everything out, then ran the hoe over the whole area. The hoe seemed to have no effect, but who knows. Completely cleansed the area, even scythed nearby grass, so 6 tiles in every direction was as blank as I could make them. Anyway, I went to sleep, woke up and logged out, and the problem was fixed when I returned.