This comes under, for what it's worth, but I was once taught to break up terra cotta flower pots and put the shards in the bottom of a planter without drainage holes, and I've done that and haven't had a problem. They're apparently so thirsty that they regulate the water level or something? I have some ceramics that my late father made, and I would brain anyone who sneezed within 20 ft. of them, so the idea of drilling holes was WAY out of the question. So it works for me.
