Clever prank at a high school
Some pranksters planted a tree at an Ohio high school. The 25 foot tall tree was planted at the baseball field, between the pitcher's mound and home plate, presenting quite a challenge for pitchers.
When I was a junior in high school, the senior class at some point fertilized a hill on campus that was visible from most of the classrooms. The fertilized in letters said (name of the school administrator) SUCKS. It was kind of ragged when the grass grew in and the letters emerged, but you could tell what is was supposed to say. Brilliant.