Attached are all files you need to make your own concrete self watering planter for a small plant. The idea is you place a single piece of cotton rope in a U shape with both ends in the upper container. Fill the upper with dirt and your plant, then fill the lower chamber with water.

To make a casting with concrete all files are ready to be sliced as is.

The only two objects to slice a specific way are the inner pieces on both objects. Print them with the larger faces up with spiral vase mode. Smaller the layer height the better. This way when the mold is done you can tear the inner pieces out easily. All other parts can be printed with 2 walls on the side, 4 top and bottom. 15% infill

Once assembled tape up the plates to both the inner and outer pieces. Pour concrete and split the mold when the concrete is done curing. Drill two holes like the top positive, 8-10mm in size. Instead of sourcing rope you can find shoe laces and find the width and size down the wholes a mm.