Is it a ‘Real’ Christmas Cactus or Not?

A brief review of readily available information will likely convince you that holiday cacti are among the most misunderstood in the gardening world. There is so much misinformation on the web–and in printed materials as well–anything one reads is likely to be different than the thing last read and will differ from the next. It is a surprise that more than one website of major research universities confuses Thanksgiving and Christmas cacti.

Distinguishing between these two major types of holiday cacti is not as difficult as it might seem. For instance, you can tell the Thanksgiving cactus from the Christmas cactus in four distinct ways. First, the Thanksgiving Cactus (Schlumbergera truncate; formerly classified as Zygocactus truncates) will almost certainly bloom a month or so earlier than the Christmas cactus—as early as October‚Äîbut usually in late November or early December, depending on the area’s climate. It’s not surprising that Thanksgiving cacti are often called a Christmas cactus because Christmas is the holiday they are likely to be in bloom for. This works in favor of the growers, retailers, and florists who take pains to ensure that the cacti available to sell at the Christmas holiday are in full bloom. It is uncertain that the real Christmas cactus (Schumbergera bridgesii) would be so reliable since its natural time to bloom is after the holidays.

Second, the Thanksgiving cactus bloom is asymmetrical–if you look straight into the bloom you will see that it is not perfectly round. The bloom sweeps downward, whereas the top of the Christmas cactus is perfectly round and has no slant to it. Third and perhaps the most evident, the segments of the Thanksgiving plant have pointed ‘teeth’ along the edges of the flat jointed stem segments and at the terminal segment. The true Christmas cactus, has leaf margins that are rounded with scallops (usually four) along the edges of the stems. The arching branches produce 3-inch-long, rosy-red flowers from late December through March.

Finally, it is easy to observe the coloration and changes in the holiday cacti’s stamen, which is often called the flower’s male reproductive organ.. In the Thanksgiving cactus, the stamen is noticeably a bright magenta color. As the blossom matures the anther, which is the pollen bearing part of the plant’s stamen, becomes more prominent and, in the Thanksgiving cactus the anther is yellow. On the other hand, in the Christmas cactus, the anther is purplish-brown and noticeably different that the Thanksgiving variety.

The holiday cactus Schumbergera cultivars differ in other following respects that are a blend of genetics and environmental factors: 1) degree of branching; 2) plant habit (pendulous, semi-pendulous, or erect); 3) rate of vegetative growth; 4) shape of segments and flowers; 5) flower color; and 6) time of flowering under natural photoperiods. However, the main criteria that consumers use to evaluate holiday cactus are flower color and number of flowers per pot or basket.

There is a wide variety of colors of Thanksgiving cacti—white, yellow, fuchsia, red, pink, lavender, peach, and orange, to name a few. But there are equally as many variations in color; for instance, two yellow Thanksgiving cacti may not be the same color, so for the serious collector and hybridizer it is becoming necessary to know the actual botanical name of the variety you are seeking. In the meantime, for the rest of us it is fun to just enjoy the beauty of these delightful plants that can brighten our world from October to March if conditions are right.