12. Haunted Greenhouse Conservatory
If you have a glass greenhouse, a garden shed, or even a covered sunroom, turn it into a haunted botanical laboratory. Fill the space with overgrown, exotic-looking plants, hanging dried herbs, and antique brass microscopes. Place glowing green or deep purple spotlights inside the structure to make the glass panes glow from within. Add a low-lying fog machine that slowly leaks mist through the door joints, creating the illusion of a mad botanist’s long-abandoned experiment coming to life.