Distinguishing Between Thanksgiving and Christmas Cacti
Learn the leaf and flower details to identify your holiday cactus correctly.
1Common Retail Mislabeling
Many plants sold in nurseries and big-box stores as Christmas cacti are actually Thanksgiving cacti. According to North Carolina State Extension, this mislabeling is widespread, leading to confusion when plants bloom earlier than expected. Clemson University confirms that the Thanksgiving variety is the most common type found during winter holiday sales.
2Identifying Leaf Margins
To distinguish the two, examine the flat stem segments. Thanksgiving cacti, known as Schlumbergera truncata, feature two to four saw-toothed projections along their margins, resembling small hooks or claws. Conversely, the true Christmas cactus, Schlumbergera bridgesii, possesses more rounded, smooth margins with a slight scallop, making them distinct from the pointed Thanksgiving variety.
3Flower and Anther Differences
If your plant is currently in bloom, check the anthers at the center of the flowers. Thanksgiving cacti typically display yellow anthers, whereas true Christmas cacti have purplish-brown ones. Additionally, the Easter cactus, a third look-alike, has oval segments with soft, rounded edges and naturally blooms during the spring season instead.
4Temperature and Bud Formation
Both plants set buds in response to specific environmental cues, primarily cool nights and long periods of darkness. Clemson University notes that maintaining night temperatures between 50 and 59 degrees Fahrenheit will trigger bud formation regardless of day length. A cool spare room or unheated sunroom is ideal for this process.
5Managing Light Exposure
Without cool temperatures, these plants require at least 14 hours of continuous darkness daily to bloom. Starting in mid-September, provide a dark environment from 5 p.m. to 8 a.m. for six weeks. Even minor light exposure, such as a lamp switched on in the evening, can interrupt the necessary cycle.
6Watering and Bud Retention
Slightly reducing water during the initial bud formation stage can encourage blooming. However, once buds appear, the soil must be kept evenly moist to prevent them from dropping prematurely. Consistent moisture is critical, as allowing the soil to dry out during this sensitive phase often results in the loss of flowers.
7Avoiding Bud Drop
Sudden temperature changes are a primary cause of bud drop. Clemson University advises selecting a permanent holiday display spot before buds appear to avoid moving the plant later. Keep the cactus away from heating vents, drafty doors, and fireplaces, as these environmental fluctuations can cause the plant to drop its buds.
8Optimal Potting Conditions
Resist the urge to repot your cactus during the blooming season. These plants prefer to be snug in their pots, often thriving when nearly pot-bound. By following these specific care guidelines regarding light, temperature, and placement, you can ensure your holiday cactus remains healthy and vibrant throughout the entire winter season.
Original article: Trendir — Distinguishing Between Thanksgiving and Christmas Cacti