Do 3D printed items absorb moisture?

I’m new to printing and trying to learn as much as I can before my printer arrives. I know that you need to have dry filament while printing, but once the item is printed does it still absorb moisture? I’ve seen a lot of 3d printed planters so I’m trying to figure out how you can water the plant without destroying the planter itself. I was planning on printing one in PLA if the material matters.