It's all how you stack it. Marco Ferreri created these great planters that are made of terracino lite, which is a "terracotta-esque composite that is more difficult to chip and crack."
These "Tuttisuperterra" planters are modular. They can be used alone, or are also able to be stacked in different configurations to make custom dividers. $295, from UnicaHome. (Unfortunately only the terracotta finish is available.)