Even though plants don't have brains, they "know" about capillary action.
If they could talk they would ask you to trash the clay pots and help move their water up by capillary action right from the start by using a sub-irrigated planter (SIP).
They would suggest that it's the smart thing to do and that stuffing them into clay pots is not a "good thing".
A Long Road to Travel
Water is absorbed from the soil into the roots of a plant. However, to reach the leaves where photosynthesis takes place, water must move upward to the top of the plant.
Water travels through long, thin tubes running up from the roots through the stems and leaves called xylem.
Water moves up the xylem through a process called capillary action. Capillary action allows water to be pulled through the thin tubes because the molecules of the water are attracted to the molecules that make up the tube. The water molecules at the top are pulled up the tube and the water molecules below them are pulled along because of their attraction to the water molecules above them.
A sponge also absorbs water through capillary action. The sponge is filled with thin spaces that act like thin tubes. Read more...