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.
Water a Christmas Cactus with care. Caring for this plant can be a bit tricky as you need to take care not to overwater or underwater it: A Christmas cactus is a tropical cactus, not a desert cactus. Unlike most desert cacti, this variety cannot tolerate completely dry soil. If the soil gets too dry, the flowers buds will drop, and the plant will wilt.