Are you allowed to have benefit from a tree which is growing on a cemeteries if not over a grave? E.g fruit tree in the car park does make a different if you use it for a mitzva fir arba minim?
Answer:
There is no prohibition against deriving benefit (and eating fruit) from trees growing in a cemetery (even it is grows over a grave).
See: Shulchan Aruch, Yoreh De'ah 368; Biur Ha-Gra, Yoreh De'ah 240 (concerning bringing fruit from a cemetery).
Best wishes.
