Small self-watering plant pot with reservoir. Simply stuff some kind of wicking material (like a paper towel or bit of cloth) through the hole in the pot and fill with dirt and water respectively. The dirt should remain moist, but not overly so, as long as the wick sits in the water.

Prusa

I3 MK3S

Doesn't Matter

Doesn't Matter

Print the reservoir with solid walls (top shells and horizontal shells) so that it doesn't leak.