In several places people have mentioned that there is a watering problem with terra cotta pots. That is, that they are great at wicking water away from the soil that is in them.
For several years, I have used plastic bags from Garden Fresh to line my terra cotta pots. For the smaller pots, I just use one bag, put it into the pot fill with soil, and trim off any thing that shows. For the larger pots, I split the bags and line the pots with them.
Doing that, I only have to water every other day, rather than once a normal day, or twice on low humidity days.