Inspired by Piojoman I made a variant.
This model shows the water level.

1. Print the part.
2. Cut open the Dolce Gusto cup. It's a bit difficult to do it nicely.
3. Remove;
   the plastic layer covering the coffee;
   the sieve that is under the coffee;
   and the coffee itself in case the plants need different soil (the purslane I tried didn't take otherwise).
4. Place the DG cup on top of the print.
5. Add the seed(s).
6. Add water regularly on the soil or in the saucer. In case of the latter the capillary effect will soak the soil.

Creality

Ender 3

No