There were many superstitions--believed by both children and adults in To Kill a Mockingbird--associated with Boo Radley and the Radley House. Negroes would not walk past the house at night; instead, they would cut across the street to the other sidewalk "and whistle as he walked." Nuts from the Radley pecan tree that fell into the schoolyard were left untouched: "Radley pecans would kill you." Birds would not sing while sitting in a Radley tree. Children who had to pass the house always ran past it; others, like Cecil Jacobs, walked a mile out of the way to school to avoid it.
And then there was Boo, the "malevolent phantom" who lived inside. Boo was said to peep in windows at night. He could kill azaleas by breathing on them. He mutilated neighborhood pets and other animals, and he would "gouge your eyes out" if he caught you.
Readers are introduced to the Radley house early in chapter one. Lee uses Dill's character to inform readers about the house, its occupants, and the associated superstitions. Readers are told that Dill has a special interest in the house.
The Radley Place fascinated Dill. In spite of our warnings and explanations it drew him as the moon draws water, but drew him no nearer than the light-pole on the corner, a safe distance from the Radley gate.
The first superstition that readers are told about is the "malevolent phantom" that lives there and haunts Maycomb, the flowers, and the windows of nearby homes.
Inside the house lived a malevolent phantom. People said he existed, but Jem and I had never seen him. People said he went out at night when the moon was down, and peeped in windows. When people’s azaleas froze in a cold snap, it was because he had breathed on them. Any stealthy small crimes committed in Maycomb were his work.
Readers are told that Negroes refused to walk past the house at night. Instead, they would cross to the other side of the street. Additional protection was achieved by whistling while walking in front of the Radley house. Kids are especially wary of the Radley house, and those fears are heightened by the house's proximity to the school. Readers are told that any nuts that fell onto school property from the Radley's pecan tree went untouched. The kids thought that the pecans were poisonous.
My personal favorite superstition is the superstition about lost baseballs. If a baseball were hit into the Radley yard, the ball was never spoken of again. It was like it never existed. I chuckle at this part every time because I had this very same experience with a neighbor when I was kid. I think that's why Lee includes this short section about the Radley house. She could have said the house was "creepy" and left it at that; however, by giving readers these superstitions, Lee reminds readers of our own childhood experiences.