The Book of Koli (The Rampart Trilogy Book One) by M.R Carey
I came across this review today https://bookliterati.com/the-book-of-koli-the-rampart-trilogy-book-one-by-m-r-carey/ and seeing as how we had read The Girl with all the Gifts a while back it intrigued me.
The blurb says:
The Book of Koli begins a breathtakingly original new trilogy set in a strange and deadly world of our own making.
Beyond the walls of the small village of Mythen Rood lies an unrecognisable landscape. A place where overgrown forests are filled with choker trees and deadly seeds that will kill you where you stand. And if they don’t get you, the Shunned men will.
Koli has lived in Mythen Rood his entire life. He believes the first rule of survival is that you don’t venture too far beyond the walls.