These are designed to fit planters you can buy from Home Depot here: https://www.homedepot.com/p/Dynamic-Design-Newbury-7-86-in-x-35-75-in-Terracotta-Resin-Window-Box-with-Saucer-NW3612LT/204500317

Print them with 3 or 4 perimeters with about 30% infill from a sun resistant filament like ASA or maybe ABS or PETG. Will only fit a 350 X 350 mm printer unless you cut it into pieces and assemble them with hardware.