The ornamental design for the trellis post, as shown and described.
FIG. 1 is a front perspective view of a trellis post embodying the present
invention having a single row of apertures;
FIG. 2 is a rear perspective view of the trellis post shown in FIG. 1; and,
FIG. 3 is an end view of the trellis post shown in FIG. 1.
The trellis post is symmetrical along its central axis and identical at its
ends. The trellis post is broken in the center to indicate indefinite
length.