EXCERPT:
According to Vin Diesel, Groot will be returning to his homeworld of Planet X in Phase 4 of the MCU. The beloved member of the Guardians of the Galaxy franchise has long been an enigma to audiences, especially those who have not read the comics. Now fans might finally be able to piece together his origin story.
Groot first premiered in the comics in 1960, and is one of the many characters to have been created by Stan Lee, Jack Kirby, and Larry Lieber. Though his first appearance had him as an enemy invader bent on human experimentation, in 2006 they reintroduced him as the heroic, noble being more akin to what is in the MCU. It was not long before he was seen as a staple of the Guardians of the Galaxy comics, making it a no-brainer that he would be featured in the 2014 MCU film about the team.
(full article)
https://screenrant.com/groot-planet-x-home-return-mcu-phase-4/
