About 5 years ago, Sheridan Cleland of MyPDFscripts wrote the below article on his blog. Soon after, the site disappeared. I wanted to keep the memory alive, because these practices by the studios have not changed. They have only become worse.
Cacti are one of my favorite types of plants to grow inside all year and outside in summer. Unfortunately, the ambient air tends to stay moist during most seasons, a condition which makes cacti unhappy. Cactus potting soil can enhance drainage, increase evaporation and provide the dry conditions that cacti favor.
The soil in subtropical deserts is usually either sandy or coarse and rocky. Plants and animals in subtropical deserts must be able to withstand the hot temperatures and lack of moisture. Shrubs and small trees in the subtropical desert usually have leaves adapted to retain moisture. Animals in subtropical deserts are usually active at night, when it is cooler.