Neigbor selling; landscaping encroachment

[Andrew Stewart]

I own a rental property and noticed a few years ago that my neigbor had started landscaping on my property and has set a wall of plants and stones to indicate the "property line" As this was in a corner any from the house and never used I didnt think too much of it. I tried to look for the survey stake from a few years back but couldn't find it. No big deal, it must have weathered away. Now the neighbors house is for sale and I remembered the encroaching landscaping. I just now considered the possibility that she had removed the stake. Now I am worried about my title. Should I go over and move the stones and dig up flowers?