All Flesh is Grass is a science fiction novel by American author Clifford D. Simak, published in 1965.

The book follows a small town in Wisconsin that is closed off from the outside world by a mysterious barrier, placed by extraterrestrial beings.

The barrier has been placed by an extraterrestrial intelligence that wants to collaborate with humans as it has with other alien races, but the town's inhabitants -- as well as, eventually, the world in general -- react to it fearfully.

[2] The book follows the experiences of Brad Carter who, unlike most of his childhood friends, has remained in the slowly declining town, and who is chosen by the alien intelligence as its spokesperson.

[5] Reviewers of Stephen King's book Under the Dome have pointed out the previous use of the plot device of a mysterious barrier in All Flesh is Grass.