A dish garden is a collection of similar plants grown in an open container. In a desert garden, the plants are all succulents. Succulents are plants that can survive in a hot, dry climate because they can store moisture in their stems or leaves during rainy periods. During drier times, succulents give off moisture much more slowly than most plants. Evaporation is slowed down by wax or hairs or by a reduced surface area. (Many succulents have a spherical shape because a sphere has the smallest surface area for a given volume.) Succulents grow naturally in semi-deserts where long, dry-periods are broken by short, rainy periods.