I didn't find this mentioned on here before and this isn't something that you would really do in "real life", but it appears that when you grow trees underground, you get some strange results. Some of the trees appear to have "ghost images" right next to the existing tree. Also, there is a "ghost tree" left behind after you chop them down until you do a relog or leave the area and return.
@red51 , is this something that can be fixed or is it just not intended for trees to be grown underground?