Thanksgiving Cactus vs. Christmas Cactus

(Originally posted December 19, 2007)

“Is there a difference?”, you may ask. Yes, there is–and it’s one of my biggest holiday pet peeves, horticulturally speaking!

With today’s mass market mentality and the ease of growth of the “Holiday Cactus”, one group of hybrids has essentially taken over the holiday market. However, the truth of the matter is that the plant that begins showing up on garden center shelves about a week or so before Thanksgiving and continues its run right on through the holidays is actually the “Thanksgiving Cactus”, or Schlumbergera truncata aka Zygocactus hybrids (also known as the Crab Claw Cactus because of its pointed lobes). This species has been readily hybridized to grow easily, flower profusely and offer blossoms in a veritable rainbow of colors, so naturally it has taken its place in greenhouses around the world as THE holiday cactus. However, there is another cactus whose beauty time has forgotten.

Schlumbergera bridgesii is the TRUE “Christmas cactus” and is the plant that my grandmother had an enormous specimen of that must have been 30 years old or so when I was just a child. Oh, how I wish I still had that beautiful, beautiful plant! I’m not sure what happened to it, but at some point it was no longer with us. Today, you can’t even find S. bridgesii except through specialty growers and mailorder catalogs. It has essentially disappeared from the mainstream market.

So what IS the difference? Well, for me it probably has a little bit to do with nostalgia and my memories of my grandmother’s plant in full bloom in the deep-seated living room window every Christmas. Grandma’s house was built of stone, with solid block walls nearly 2 feet thick. The window sills were the depth of the walls and one side of that Christmas cactus filled the entire depth of one window while the other half hung out into the living room. It must have been 3 feet wide. But the real difference, botanically speaking, is that Schlumbergera bridgesii or what I refer to as the “true” Christmas cactus, has rounded lobes on its leaves rather than the pointed, claw-like lobes of the cactus we commonly see being sold during the holidays.

Also, Schlumbergera bridgesii comes in but one color–Christmas red (referred to as cerise in some books). It also has a naturally delayed flowering period that pushes it back to the season of Christmas. Rarely, if ever, does it flower at Thanksgiving. As if that wasn’t enough distinguishing characteristics, its flowers are also shaped differently–without the reflexing petals and one sided flowers of Schlumbergera truncata, the Thanksgiving or “Holiday” cactus. Instead, the flowers of the true Christmas cactus have petals that are evenly distributed around the flower tube.

I can remember Granny’s huge specimen having literally hundreds of beautiful red blossoms on it each year! It would summer outdoors in the shade of the screen porch, go upstairs when the weather turned cold and then come back down to the living room during Christmas where it greeted visitors from its perch in the window. It had grown so large and so old that it had a trunk on it whose base was probably a good three inches in diameter, with several 1 to 1 1/2-inch diameter branches emerging from it, each of those in turn cascading out to form the “canopy” of the plant. The brilliant red blossoms were borne at the ends of the flattened stems (called cladophylls) and hung downward, giving a magnificent cascading effect to the plant.

The plants you buy today are manipulated in the greenhouse to flower at a certain time by adjusting the amount of day and night that they are exposed to–just like poinsettias. And because all of the hybrids have been bred to be compact, easy-to-flower and to come in a wide array of colors, the Thanksgiving Cactus (Schlumbergera truncata or Zygocactus) has become the industry standard. However, I would recommend to you that you do a little research and find a source, even if it’s mail-order and you can only find small plants, for the “true” Christmas cactus, Schlumbergera bridgesii. It will be well worth your effort!