The ornamental design for a grow box, as shown and described.
FIG. 1 is a front elevational view of a grow box showing our new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a top, front and left side perspective view thereof;
FIG. 8 is a top, front and right side perspective view thereof; and,
FIG. 9 is a top, front and left side perspective view showing the grow box in an alternate environment of use.
The broken lines in the drawings depict portions of the grow box that form no part of the claimed design. The additional broken lines shown in FIG. 9 depict environment only and form no part thereof.