how to get pokeball behind gym eterna city

[Muk]

There is a pokeball behind the gym in eterna city, to the right. It is surrounded by tress on all sides and a wall to the left. It wont let me use CUT on the trees. How do I get to this pokeball

[Justin]

Go to the LEFT of the gym, and to the North, where the trees are. then go RIGHT in between the rows of trees. This will take you inside the trees and youll be able to get the pokeball.