there's something very nice about plant pots. the colour, the shape, and of course the material. here's why terracotta is so perfect for plant pots:
Terra-cotta (unglazed clay) pots are made of a particular soil and fired in kilns during the manufacturing process. The rusty brown color of clay is harmonious with every flower and foliage color.
Clay pots provide a healthy environment for most plants. The porosity of clay allows air and moisture to penetrate the sides of the pot. This moisture and air is utilized by the fine roots located at the edge of the soil ball. Clay pots also act like a wick to remove excess moisture from the potting soil. This can be looked at as both an advantage and a disadvantage depending upon your watering habits.
Gardeners with a heavy hand at watering tend to over-water; their plants will probably benefit from clay. Plants which demand a well-drained, dry soil like cacti also prefer clay pots.
Outdoor usage of clay also has advantages. Clay pots have thick walls that protect plant roots from rapid changes in temperature which can be destructive. They also have a fair amount of weight and do not blow over as easily as some plastic pots.