Rabidgardener: What type of potting medium do you have them planted in? Do you change the soil when you purchase the plants or just leave them in the original pot with the original soil? I've found that most wholesale nurseries plant in a very dense, water retentive soil which does not allow enough air circulation around the roots of the plants; that dense soil also retains too much water which can cause root rot. A nurseryman once told me the reason for the heavy soil is because of the amount of time some plants will be sitting on shelves at the garden centers without employees watering them. I see the opposite of that at garden centers here, the plants get watered too often and without proper drainage many are almost to the point of floating in water. We had more than 5 inches of rain one day last week and the next day I was at one of our big box stores and noticed an employee in the garden center watering plants that were already saturated from so much rain.
My holiday cactus are kept one the dry side but I repot every plant I get into a chunky, well draining medium and the plants are kept on my screened porch year-round where it's quite humid.
