Robert Bishop 
Frederick County Master Gardener Program

Holiday cactus, (Schlumbergera truncata; S. bridgesii; S. russelliana) also known as Christmas cactus or Thanksgiving cactus are often given as gifts for the holidays and received while blooming. There are over 200 hybrids available which result from cross breeding different species. They are native to a mountainous region in Brazil, just north of Rio de Janeiro and are true cacti even though they lack the familiar spines. The stems of this plant are flat and jointed with deeply toothed margins that resemble leaves. Holiday cacti are shade loving plants that flower for 4 - 6 weeks starting around mid-November. Many hybrids are in bloom for Thanksgiving.

I have spoken with numerous people that have problems getting the cacti to flower again after first receiving them. The most common cause for this is the length of time the plants receive light each day. Flower production in induced by the day length, just like the poinsettia. The naturally occurring short days of fall and winter trigger flowering. Holiday cacti that are kept in artificially lighted rooms flower poorly or not at all. Either cover them when the sun goes down each day or move them to a room that most often remains dark at night, closets work well. The amount of light received should not exceed 9 - 12 hours each day. This variance is due to the light sensitivity differences of the many available hybrids. To be sure, limit the light exposure time to a maximum of 9 hours, unless you know the particular requirements of your hybrid.

Room temperature, light intensity, and soil moisture will also affect flowering slightly. Flower buds will drop off below 50 degrees, and will not open below 60 degrees. If the light intensity (strength) is too low buds will not open either. Although cacti do not require large amounts of water, flowers and buds will drop off if the soil becomes too dry.

Generally holiday cacti are easy plants to care for. Place them in an east, south, or west window. Keep plants uniformly watered and fertilized during the summer months. (Use a fertilizer formulated for cacti.) Flowers develop on the tips of new stems in autumn and winter. To insure flowering, stop watering at the end of summer and keep plants between 50 - 55 degrees. Limit the amount time plants receive light to less than 12 hours each day. Once buds are present increase temperature to 60 - 70 degrees and resume moderate uniform watering to get buds to open. Maintain soil moisture, light, and room temperature while plants are flowering. Flowers that open in autumn are paler in color than those that bloom later in winter.

The goal of any breeding program is to produce better plant characteristics. Holiday cactus hybrids are selected for larger flowers, better colors, and ease of growing. Some of the more popular hybrids are:

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