This is the cactus I gifted my grandparents about 18 years ago.
Terasa Lott, ©2019, Clemson Extension
The Poinsettia may be the most iconic holiday plant, but the Thanksgiving cactus is my favorite because of its sentimental value. About 18 years ago, I purchased what I thought was a Christmas cactus for my grandparents. They traveled for an extended period that summer and accidentally put the cactus in the outdoor shed. Thankfully, I had decided to do some landscaping while they were gone and discovered the sad-looking cactus before it was too late. Although both of my grandparents have passed away, I still have the original plant, which graces us with bright magenta flowers each year around Thanksgiving.
Holiday cacti are available in a variety of solid colors ranging from almost white to red as well as a few bicolor like the one pictured here.
Terasa Lott, ©2019, Clemson Extension
The flowering time is a clue that this treasured plant is not a Christmas cactus (Schlumbergera x buckleyi) but a Thanksgiving cactus (Schlumbergera truncata). In fact, I have yet to see a Christmas cactus on a store shelf, even if the tags say otherwise. In addition to the timing of flowering, there are other features that distinguish the two.
- The stem segments (phylloclades) on the Thanksgiving cactus have distinctly pointed edges, while the stem segments of the Christmas cactus are more rounded.
- The anther, which bears the pollen, is yellow on a Thanksgiving cactus but purplish-brown on a Christmas cactus.
The color of the pollen bearing anther can be used to distinguish Christmas and Thanksgiving cactus. Thanksgiving cactus have yellow anther as pictured here compared to the purplish-brown anther of Christmas cactus.
Terasa Lott, ©2019, Clemson Extension
If your holiday cactus isn’t flowering, it’s probably related to light. Holiday cacti are short-day plants. This means they require a period of uninterrupted darkness to trigger a bloom cycle. Indoor lighting and even streetlights shining through a window can interrupt the dark cycle required for flower formation. To flower, relocate your plant for 8 weeks to an area where it will receive 13 hours of dark daily.
Distinctly pointed margins of the phylloclades indicate this is a Thanksgiving cactus.
Terasa Lott, ©2019, Clemson Extension
One great characteristic of holiday cacti is the ease of propagation. A few years ago, I pinched several sections containing 3-5 stem segments, allowed them to callus, and placed them in well-drained potting soil. If something should happen to the mother plant, I will still have a piece of it and the treasured memories it holds. See HGIC 1554, Thanksgiving & Christmas Cacti for more detailed information on the care and propagation of these popular holiday plants.
For more information on other holiday houseplants, please see HGIC 1561, Poinsettia, HGIC 1551, Amaryllis, HGIC 1564, Cyclamen, and HGIC 1563, Kalanchoe.
Reference:
MSU Extension Gardening in Michigan: How to Care for and Get Your Holiday Cactus to Rebloom.
