The ornamental design for a decorativeplanter, as shown and described.
FIG. 1 is a front perspective view of a decorative planter showing my new design;
FIG. 2 is a front side elevational view thereof, the rear, left side, and right side elevational views being identical;
FIG. 3 is a top plan view thereof; and,
FIG. 4 is a bottom plan view thereof.
The dashed phantom lines are provided for environmental purposes only illustrating the decorative planter in conjunction with a media tower having a pair of opposing display screens mounted near the upper end of a box truss structure and a pair of opposing billboards mounted at right angles to the display screens at a lower position on the box truss. These dashed phantom lines do not form a part of the claimed design.