Although true cacti, these plants are native to rain forests. The need for high humidity, bright but filtered light, and soil kept relatively moist most of the year, sets these plants apart from the majority of cacti and succulents.
These three cacti can be differentiated from one another by examining the sections (cladophylls) of the plant. A Thanksgiving cactus (Schumbergera truncate) has longer more pointed cladophylls; Christmas cactus (Schlumbergeraa bridgesii) has rounded cladophylls; the Easter cactus has very rounded cladophylls.
These plants are very long-lived. It is common to hear of these plants being passed on from generation to generation and sometimes living over 100 years. Though called Thanksgiving, Christmas and Easter cactus, these common names are primarily for marketing purposes and provide only a general reference for the time of year these plants may bloom.
Holiday cacti are called “short day plants,” meaning in order to produce flower buds they require shorter days (fewer hours of light) and/or cool night temperatures. Locate holiday cacti indoors in a cool, bright location where daytime temperatures are 65 to 70 degrees F, and evening temperatures are 55 to 65 degrees F. If plants are exposed to cooler night temperatures of 55 degrees F, plants will bloom in approximately five to six weeks—sometimes regardless of the day length. If night temperatures are 60 to 65 degrees F, these plants must have at least 12 hours of complete darkness every night for about six weeks in order to bloom. Plants are unlikely to bloom if exposed to night temperatures above 65 degrees F.
Holiday cacti require good drainage and aeration for healthy root growth. Remove excess water from saucers and decorative pots when watering. Allow soil to dry out between watering; soil should not be heavy as this may result in dropping flower buds, wilting and ultimately root rot.
Once flower buds have started to develop, holiday cacti do not like to be disturbed. Plants may drop buds due to drafts or sudden changes in temperature or humidity levels. If the plant is to be displayed in a warmer room than the one in which the buds were initiated, move it there as soon as buds appear.
After plants have finished blooming, water less frequently, increasing again in spring when plants resume more active growth. Fertilize monthly, June to August, with a balanced houseplant fertilizer at half-strength. In the fall, change to a fertilizer with low nitrogen and high phosphorus and potassium such as 0-15-10.
This information was taken from the University of Minnesota Extension article on Holiday cacti. For more information, and solving common problems, go to the Extension website on Holiday cacti. Now is the time of year to start fertilizing your plant more heavily and watch for bud development.