Gardening 101: Christmas Cactus

Christmas Cactus, Schlumbergera bridgesii: “Magic in Maine”

The Christmas cactus is a plant of magic and mystery. My parents had one when I was growing up, a large sprawling specimen that lived in a terra cotta pot and would drop red blossoms onto the windowsill every winter. It bloomed at Christmastime (according to its name) but, very strangely, would usually bloom again in early spring. Sometimes it would die completely before coming vibrantly back to life the next December. Now I know that this magical pattern actually was due to  thermo-photoperiodic bloom cycles, meaning cold and darkness cause it to flower: a perfect plant for long Maine winters. Here’s everything you need to know about this mystical plant.

Christmas Cactus belongs to the Schlumbergera genus, a small genus of flowering cacti that only has six species. The genus was discovered by Charles Lemaire in the mid 1800s and is named after the French cacti collector Frederic Schlumberger.

A true Christmas cactus has smooth, almost scalloped stems and tiered blooms.

Christmas Cactus is native to Brazil, where it (along with the rest of the Schlumbergera gang) is referred to as “Flor de Maio” because of a predilection to bloom in May. For most of the rest of the year, the Christmas cactus is fairly innocuous but come winter, it suddenly bursts with color and blooms.

The plant is leafless, and instead has flattened, segmented, slightly spiky stems, each with an areole from which a flower grows. The flowers are most often pink, white, or red. They are tiered and sometimes look like flowers within a flower.

Oddly enough, there’s also a Thanksgiving cactus (Schlumbergera truncate, also called “crab cactus”). The two are commonly confused; in fact, what’s sold as a Christmas cactus might well be a Thanksgiving cactus. An easy way to tell them apart: The stems of a Christmas cactus have smooth, rounded edges, while the stems of a Thanksgiving cactus are spiky, almost prickly. The Thanksgiving cactus tends to bloom in late fall rather than early winter.

Cheat Sheet

• Christmas cacti flower according to light and temperature cues: to bloom, they need cool nights (around 50 degrees Fahrenheit) and more than 13 consecutive hours of uninterrupted darkness. To encourage the cactus to bloom, turn off lights at night. You also can cover the plant with a black cloth or set it in a dark closet overnight.
• Christmas cacti usually bloom naturally at the beginning of winter. Buy one a few months before the season begins.
• If you’re feeling particularly festive, string Christmas cacti or their pots with white twinkle lights during the holidays.

Keep It Alive

• Don’t leave Christmas cactus high and dry: Unlike typical cacti, this plant is actually native to the rainforest. Water it when the top inch of soil is dry, but be sure that there’s no excess pooled in the pot. Water slightly more frequently (but do not change the volume) when the plant is in flower.
• Make sure your home is well-humidified; in keeping with its tropical habitat, Christmas cacti thrive when there’s moisture in the air. (Keep this in mind if you have a fireplace or wood stove.)
• Keep Christmas cactus in bright light during the day, but be sure it doesn’t burn—a windowsill is a good place.

Christmas cacti can live for decades, making them excellent candidates to pass down to the next generation to create a family holiday tradition.

For more festive plants to deck the halls, see our posts:

• Poinsettia: Rethinking a Traditional Christmas Flower.
• A White Christmas, with Potted Cyclamen.
• 10 Easy Pieces: Garlands and Boughs to Deck Halls.

Finally, get more ideas on how to successfully plant, grow, and care for christmas cactus with our Christmas Cactus: A Field Guide.

Finally, get more ideas on how to plant, grow, and care for various houseplants with our Houseplants: A Field Guide.

Interested in other succulents or cacti? Get more ideas on how to plant, grow, and care for various succulents and cacti with our Succulents & Cacti: A Field Guide.