This spiral design is inspired by other pots online, and the casting idea is based off a YouTube video I saw.
You can print the pot itself and use it as is.
If you want to cast this out of concrete or plaster, then you need to print out parts A,B,C,D, and the core.
They go together in a clockwise order starting with A at top left. Once the core is in then tape the sides together until it is rigid.
I did not need to destroy the mold to get the plant pot out of it as I lubricated the sides with petroleum jelly (Vaseline).
The author hasn't provided the model origin yet.