Thanksgiving cactus (Schlumbergera truncata) and Christmas cactus (Schlumbergera bridgesii) are popular, fall- and winter-flowering houseplants native to Brazil, and are available in a wide variety of colors including red, rose, purple, lavender, peach, orange, cream, and white. These Schlumbergera species grow as epiphytes among tree branches in shady rain forests, and their pendulous stems make them a great choice for hanging baskets.

When grown under normal night length conditions, Thanksgiving cacti normally flower near Thanksgiving approximately a month before Christmas cacti bloom. Another member of the group sold as holiday cacti is the Easter cactus (Rhipsalidopsis gaertneri), which flowers primarily in the spring and sporadically throughout the year with pink or red flowers. Because of its bloom time, the Thanksgiving cactus is most predominately encountered for sale during the winter holiday season. Flowering can last up 7 to 8 weeks if the plants are kept at 68 ºF.

To distinguish between the Thanksgiving and Christmas cacti, look at the shape of the flattened stem segments, which are botanically called phylloclades. On the Thanksgiving cactus, these stem segments each have 2 to 4 saw-toothed serrations or projections along the margins. The stem margins on the Christmas cactus are more rounded. Note that there are no true leaves on either of these holiday cacti, so photosynthesis occurs within the green phylloclades.

A second method to distinguish between these two Schlumbergera species is based on the color of the pollen bearing anthers. The anthers of the Thanksgiving cactus are yellow, whereas the anthers on the Christmas cactus are purplish-brown.

Fact sheet: Christmas Cactus

Sold at Nassau County Master Gardener Plant Sale