User blog comment:Woest/Great Tree Arc and Green Magic/@comment-1359322-20131125004331

Walrod did say he wasn't specialized in combat so maybe his magic is more on giving those type of "divine protection" on people using his tree/plants. And when Mavis died, Walrod planted the tree in the island alongside Mavis' grave as a farewell gift or some sort to Mavis and the future members of Fairy Tail.