How have you dealt with the fact that terra cotta pots wick so much water from the soil?

You are so right, Terra cotta does wic moisture away. I have two solutions. The first is use a spray sealant on the pots. You can use polyurethane (spray) on the outside of the flower pot. The second is using some of those moisture additive beads to the soil. They plump up when wet and hold a lot of water. Good luck with your pots!