The ornamental design for a blank for a plantcontainer liner, as shown and described.
FIG. 1 is a top plan view of a blank for a plant container liner with the
bottom view being identical thereto;
FIG. 2 is an elevated front view of the blank for a plant container liner
shown in FIG. 1;
FIG. 3 is an elevated back view of the blank for a plant container liner
shown in FIG. 1; and,
FIG. 4 is a left side view of the blank for a plant container liner shown
in FIG. 1, the right side view being identical thereto.
The broken line, showing of the dotted and dashed line, is represented the
fold line and is for illustrative purposes only and forms no part of the
claimed design.