Thanksgiving cactus (Schlumbergera truncata) and Christmas cactus (Schlumbergera bridgesii) are true cacti that grow as epiphytes among tree branches or rocky spots in the coastal mountains of south-eastern Brazil.

Schlumbergera truncata
Photo: Schlumbergera Truncata - Wikimedia Commons

Their trialing stems make them a great choice for hanging baskets.

by John Bagnasco

Colors include red, rose, purple, lavender, peach, orange, cream, and white, with blossoms from late October through November for the Thanksgiving cactus. In Brazil, the plants referred to as Flor de Maio (May flower), reflecting the period in which they flower in the Southern Hemisphere.

Now is the time that they are readily available at local garden shops. When grown under normal night length conditions, Thanksgiving cacti normally flower near Thanksgiving approximately a month before Christmas cacti bloom. Confusion often arises as retailers are quick to label S. truncata as a “Christmas” cactus, causing purchasers to wonder why their plant is all bloomed out by Christmas.

To distinguish between the Thanksgiving and Christmas cactus, which does bloom from Christmas into January, look at the shape of the flattened stem segments. 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. A second method to distinguish between these two Schlumbergera species is based on the color of the pollen bearing anthers. Those of S. trucata are yellow, while the anthers on the Christmas cactus are purplish-brown. Both types are relatively easy to care for as houseplants.

Here are some tips for successful cultivation:

  • Growing medium - Since the plants grow in trees or on rocks, the soil should be fast-draining with an inert material such as grit, sharp sand or perlite. It is recommended that plants should be grown in relatively small pots; half-height azalea pots are suitable.
  • Keep in mind they also prefer temperatures between 60 and 70 degrees F. with some humidity. Placing a tray of pebbles filled with water beneath is a good way to increase humidity.
  • Keep out of hot sun.