Hopper goes out to Merrill's pumpkin farm to investigate the dead crop in episode 2x01 “Chapter One: Madmax”. Dr. Owens and the team from the lab collect samples of the blight in episode 2x03 “Chapter Three: The Pollywog”. Hopper heads back out to the farm and digs down to the tunnels in episode 2x04 “Chapter Four: Will the Wise”.
Appears in 2 additional episodes.
Chapter Five: Dig Dug
Will guides Joyce, Bob, and Mike to the farm where they find Hopper's car and hole.
Chapter Nine: The Gate
The kids head to the farm to head down into the hole.