Nathan Radley said that when a tree is dying you fill is with cement to save it.
They can not because the knothole is filled with cement by Mr. Radley
He tells them the tree is dying.
Mr. Radley filled the knothole up with cement.
Jem and Scout saw that someone had filled the knothole with cement, sealing off their secret gifts from Boo Radley.
The knothole game ends when the knothole tree is destroyed by the authorities, and the children lose their secret meeting spot in "To Kill a Mockingbird" by Harper Lee. This signifies the loss of innocence and the end of childhood for Scout and Jem.
Nathan Radley tells Jem that he filled in the knothole with cement because the tree was dying and he wanted to stop it from spreading. In reality, he likely did it to prevent Boo Radley from continuing to communicate with the children.
Mr. Radley was responsible for the knothole incident because he filled it with cement to prevent communication between Boo and the Finch children. This actions caused Boo to feel isolated and cut off from the outside world.
The children find small gifts in the knothole of the tree, including two carved soap figures that resemble them, a pack of gum, and shiny pennies. These gifts are left by Boo Radley, who is trying to reach out to the children in a secretive way.
Jem is crestfallen when he discovers that the knothole in the tree has been filled with cement. He is disappointed and saddened by the destruction of their secret communication spot.
Mr. Radley puts cement in the knothole to prevent any further communication or interaction between Boo Radley and the children. This action is driven by his desire to isolate Boo Radley from the outside world.
Jem and Scout discovered that someone had filled the knot hole with cement, sealing off the opening where gifts had previously been left for them by Boo Radley. This action by Nathan Radley signified the end of their secret communication with Boo.
Nathan Radley, Boo Radley's brother filled the knothole with cement. When Jem and Scout asked him why he was doing this he told them that his tree was dying and filling the knothole with cement would keep it from dying. Scout and Jem went and asked Atticus if he thought the tree looked like it was dying and he said it looked perfectly healthy.