The ornamental design for a pot for a verticalgarden, as shown and described.
FIG. 1 is a perspective view of a pot for a vertical garden showing our new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a side view thereof; and,
FIG. 7 is a side view thereof.
The broken lines in the figures are included for the purpose of illustrating portions of a pot for a vertical garden and form no part of the claimed design.