Christmas cacti are often great choices for hanging baskets - thanks to their pendulous stems. When in full bloom, you can gift them to your loved ones or use them for home decoration. In this Christmas cactus care guide, you're going to learn how to "trick" your plants to thriving and flowering profusely.
You're explicitly going to learn how to manipulate light and temperature to trigger colorful blooms, when and how to water your Christmas cactus, repotting, fertilization, and common problems to look out for.
While easy to grow, Christmas cactus can be frustrating to re-bloom, especially for newbies. However, thanks to the information in this definitive guide, you'll find it easy to successfully grow them indoors throughout the year.
If this sounds like something you'd want to read about, then let's begin:
Christmas Cactus Fact Sheet
Christmas cactus, also botanically known as (Schlumbergera x buckleyi), is a popular holiday flowering houseplant native to Brazil. Other holiday cacti include; the Thanksgiving cactus (Schlumbergera truncate), which is the most common, and the Easter cactus (Schlumbergera gaertneri)
In their native environment, they grow as epiphytes among tree branches in shady rain forests. Although they have the name 'cactus,' their care is quite different from the desert relatives.
The flowers, which come in a wide range of pink, red, purple, white, orange, cream, and peach, can last between 7 and 8 weeks if the plants are kept at approximately 68°F.
If you want to differentiate between a Christmas cactus and a Thanksgiving cactus, look at the stem's shape. The Christmas cactus stem margins are more rounded. Also, the Christmas cactus has purplish-brown pollen-bearing anthers.
Easy Christmas Cactus Care Strategies
Watering a Christmas Cactus
When and How to Water your Holiday Cacti
The best way to determine when you should water your holiday cactus is to poke your finger about an inch and feel if the soil/mix is dry. Alternatively, you can get inexpensive watering gauges to help you determine when there's a moisture deficit in the potting mix.
If there is a deficit or the top inch of the mix in the container feels dry, it's time to water the plant.
You can water a Christmas cactus from the top or bottom. However, keep in mind that after subsequent bottom-up watering, it's essential to periodically water from the top to flush out any salt build-up.
When watering from the top, soak the soil until water drains through the container's drainage holes. You need to allow the potting mix to dry completely before watering again. Make sure you water your plants early morning or early afternoon to give them enough time to dry before the night.
Watering is vital, especially during the flowering period. However, don't let the plant sit in standing water since this will cause waterlogging and root-rot.
How Often to Water your Christmas Cactus – Watering Frequency
There's no definite answer on how often you should water your Christmas cactus plant. The watering frequency depends on several factors such as the pot or plant's size, the composition of the potting mix, sunlight intensity, and temperature.
The best advice I can give you when it comes to watering frequency is – don't have a watering schedule. Instead, follow a need-based watering strategy, which you can determine by feeling the soil or using a moisture gauge.
In general, you can tell if your Christmas cactus is overwatered by looking at the stem branches. Branches drooping or breaking is a sure sign of over-watering.
How to Get a Christmas Cactus to Flower/Bloom
When it comes to Christmas cactus care, most people are more concerned with maintaining or triggering the brightly colorful and eye-catching flowers that come in various colors.
The "trick" to achieving this otherwise elusive endeavor boils down to what is referred to as; the ying and yang of plant life. In other words: light and temperature. These two vital elements are central to all flowering plants since, in their right balance, they trigger florigen – a hormone responsible for blooming.
This is the same concept I used to develop what I call "The Ball Rolling Technique" in my book about How to Grow African violets that Bloom 365 Days a Year. It is a mathematical formula between light and temperature that sets the stage for massive flowering.
Luckily, the same concept can be used in this case:
To trigger Christmas cacti into flowering, provide a cool environment with a short day cycle. You can achieve this by providing them at least eight days of 16 hours of dark and eight hours of light each day.
To achieve the hours of darkness, place the Christmas cactus in a completely dark room each night or cover it with a dark piece of cloth or box for an extension.
It's important not to turn on the lights at night or remove the cover, even for a short period – since the dark cycle required will break.
You should place your plant in a sunny location indoors. An east or north-facing window gives the ideal light. If you want to grow the Christmas cactus indoors in west or south-facing window, you should shade the plant with thin curtains to avoid direct sunlight.
Once the light is right, strive to maintain the temperatures between 50 to 61°F. The Flowers will start to form when the temperature is between a cool 50 - 61°F (10 to 14°C).
Also, keep in mind that the active growth commences once flowering has stopped. Therefore, it's necessary to allow Christmas cactus some reasonable resting period between each flowering cycle.
To summarize this point, provide the following conditions if you want to get your Christmas cactus to bloom:
- For eight days, provide 8 hours of light and 16 hours of darkness.
- Cool temperatures of 50 - 61°F (10 to 14°C).
After blooming is done and you've enjoyed the flowers, let the plant rest by withholding water for six weeks. Then, resume watering to keep the soil reasonably moist but let the surface dry out moderately.
Create a Humid Environment to Prolong the Flowering
As we've already discussed, these plants natively grow as epiphytes among tree branches in shady rain forests – where they receive high levels of relative humidity.
Hence, humidity is vital to Christmas cactus, much more so during flowering. To replicate the native humid conditions, place the container on a tray of pebbles. Add clean water to the tray to increase humidity around the plant.
Alternatively, you can get cheap plant humidifiers sold commercially online or in garden centers.
Keep caring for your plant this way until the plant finishes blooming.
Christmas cactus pruning
Once all the flowers have been spent and just before the beginning of active growth, this is the right time to prune your Christmas cactus. Begin to prune a week after all the flowers have dried out.
During this period, pruning the cactus will encourage the plant to branch out and become denser when it begins to grow actively.
To prune a holiday cactus, use a small, sharp-well disinfected pruner or knife to cut plants where two branch sections (cladophylls) join. Alternatively, twist the stem at the narrow joint between leaf segments.
The Christmas cactus plant will produce 1 to 2 new cladophylls where it was cut and increase its branching.
You can take this opportunity to shape the plant the way you want by lightly pruning a few segments. Make sure you don't this at once but rather remove up to one-third of the plant every year – to achieve the desired shape and size.
Feel free to propagate more Christmas cacti plants from the extra cuttings.
When to Repot your Christmas Cactus
The best time to repot unhealthy or struggling Christmas cactus is any time of the year. Don't wait as most of the time, the problem is always with potting soil and subsequently with the roots.
However, under normal circumstances, you can repot the plant every two or three years or whenever the container is root-bound.
After changing your plant into a fresh, well-draining potting mix, follow up by applying 1/2 the recommended liquid houseplant fertilizer rate every 2 to 4 weeks.
When the temperature rises, especially during the summer, you can move your Christmas cactus outdoors, porch, or patio but keep it in a partial to a full shaded area. Direct sunlight can burn the leaves.
Fertilizing a Christmas cactus/Potting Mix
When you Should Feed your Christmas Cactus and How
Before we explore how and when you should fertilize your plants, it's critical to mention that, well-draining potting mix is a must for healthy Christmas cacti. Instead of using any soil, get a commercially packaged potting mix recommended for succulent plants.
The best time to begin fertilizing your plants is when new growths start. Please give them a half-strength liquid houseplant fertilizer with trace elements. A good example is a 20-20-20 fertilizer.
It would help if you continued with the same regime every two weeks until the beginning of flower bud formation. Once the first bud appears, don't give any fertilizer; instead, water as directed before to keep the leaves from wilting.
Most holiday cacti have a higher requirement for magnesium than many other plants. Hence, supplement your fertilizer regime with Epsom salts (magnesium sulfate) mixed at one teaspoon per gallon of water. But make sure you don't apply Epsom the same week as regular fertilizer.
Common Christmas Cactus Problems
Christmas cactus limp leaves after flowering
While there may be other underlying reasons, this may indicate dehydration – mostly caused by too much light and too little water in the potting mix.
Make sure you water the plant properly, as we've already discussed. But first of all, make sure to check the soil whether it's dry or not.
Christmas cactus problems – leaves turning yellow
Yellowing of the branches or leaves is almost always a symptom of root rot. This is primarily caused by over-watering your Christmas cactus, thereby creating a conducive environment for the disease.
Phytophthora sp. – the pathogen responsible for root rot disease thrives well when the soil is over-watered and soggy. Ensure proper drainage of the soil and water only when necessary.
Christmas cactus not flowering
Several factors prevent your Christmas cactus from flowering. The most important being lack of enough light and darkness hours required to trigger flower formation.
The second is high or fluctuating temperatures, and lastly, low relative humidity.
You can read how to get your Christmas cactus to bloom section above for information on flowering.
Christmas cactus buds falling off
Plants have their survival mechanisms just like we do. If you see the buds falling off, know something is not right. Either there's a sudden change of the environment, for instance, they have been moved, or temperature has fluctuated drastically.
Other factors that could cause stress to your Christmas cactus include either over-watering or under-watering, lack of enough humidity in the environment, and too much fertilizer at the bud formation stage.
Pest and Diseases
Christmas cacti are susceptible to several diseases, mostly fungal issues. Among these diseases is Basal stem rot caused by Fusarium oxysporum, Botrytis blight caused by Botrytis cinerea, Impatiens Necrotic Spot Virus, Phytophthora root rot caused by Phytophthora parasitica.
There's a handy guide on how to identify and manage these diseases. Therefore, instead of writing all about it, let me just link to it – Christmas cactus diseases, identification, and management.
Conclusion
This is one of those plants that can grow for years. When you take good care of it, you can pass it on to your future generations or even friends.
Besides, you can always propagate more plants and share them as gifts to friends, colleagues, and relatives during holidays or other special occasions.
I hope this article has given you all the information you need to succeed. But most importantly, the tips and tricks you need to trigger Christmas cacti into flowering like never before.
Good luck with Christmas cactus care and happy gardening!
Resources
NC Cooperative Extension
Home & Garden Information Center – Thanksgiving & Christmas Cactus
Michigan State University – College of Agriculture & Natural Resources