Rootless by Chris Howard

17-year-old Banyan is a tree builder. Using salvaged scrap metal, he creates forests for rich patrons who seek a reprieve from the desolate landscape. Although Banyan's never seen a real tree--they were destroyed more than a century ago--his missing father used to tell him stories about the Old World. 

Everything changes when Banyan meets a mysterious woman with a strange tattoo, a map to the last living trees on earth, and he sets off across a wasteland from which few return. Those who make it past the pirates and poachers can't escape the locusts . . . the locusts that now feed on human flesh.

But Banyan isn't the only one looking for the trees, and he's running out of time. Unsure of whom to trust, he's forced to make an alliance with Alpha, a beautiful, dangerous pirate with an agenda of her own. As they race towards a promised land that might only be a myth, Banyan makes shocking discoveries about his family, his past, and how far people will go to bring back the trees.