In "Mending Wall," by Robert Frost, how do fences makes good neighbors?

Poet Robert Frost uses the wall as a metaphor to symbolize
many things in his famous poem. In its concrete form, the stone wall serves to unify its
neighbors each spring when the ground thaws, causing a swelling in which many of the
stones are dislodged. The neighbors, who rarely speak or communicate during other times
of the year, work together on opposite sides of the wall, mending its damaged sections.
The word "mending" also serves to help the neighbors reconnect verbally each spring,
patching up a friendship that is based entirely upon their shared stone fence. The
phrase "Good fences make good neighbors" is totally appropriate: Rather than leave the
fence to further deteriorate after each winter ends, the two men repair the fence,
thereby making it good again; by working together, the two men maintain their
neighborly, if otherwise distant, connection.