The ornamental design for plant pot liners and parts thereof, as shown and described.
2. Plant pot liner
2.1is a front elevational view of a plant pot liner, according to a new design;
2.2is a right elevational view of the plant pot liner shown in 2.1;
2.3is a back elevational view of the plant pot liner shown in 2.1;
2.4is a top plan view of the plant pot liner shown in 2.1;
2.5is a perspective view of the plant pot liner shown in 2.1; and
2.6is a bottom plan view of the plant pot liner shown in 2.1.
The left side views of the designs are omitted because they are mirror views of their respective left side views; the parts colored in semi transparent grey color and delineated with dashed lines are not part of the claimed designs; the texture of the articles as shown in the representations is not part of the claimed designs.