Christmas cactus is an epiphyte of the genus Schlumbergera (Cactaceae) and is native to the mountainous regions of Brazil.
Due to its short-day habit (blooming when nighttime is longer than a certain number of hours), it buds in November as the days get shorter and blooms in December.
In this article, I will discuss what causes flower buds to fall off, what causes them to bloom, and how short-day treatment can help.
Contents
What Causes Christmas Cactus Flower Buds to Fall Off?

The cactus is a delicate plant, so fluctuations in temperature and the amount of sunlight it receives can cause it to either not produce flower buds or cause tiny buds to fall off.
It would be best to keep your Christmas cactus outside, except in the winter. When the buds start to grow and change color, the temperature drops, and it gets colder, but if you hurry to bring it inside or move it to another spot, the buds will fall off.
You should take your time bringing them into the toasty living room and put them in the foyer or a hallway. Allow them a week or so to adjust before putting them in a room.

This is because the buds of a cactus are susceptible to changes in their environment. It is okay if the temperature gradually changes in the exact location. Also, be careful to move the place sparingly.
Still, if the temperature, intensity, or duration of sunlight suddenly changes due to a location change, the buds will drop. So, if you want to keep the plant from getting too cold, move it before the buds show up.
The flower buds are more likely to fall off when small (less than an inch in diameter), so it is best to avoid moving the pot during this time.
However, after the buds have reached over an inch in length (including the petals) and begun to open, they will not fall off even if you move the pot.
So, when you buy, choose a variety with buds of the same size as much as possible.
Be Wary of Overheated Rooms!
Keep your Christmas cactus away from scorching areas, as this is one of the causes of flower bud drop.
They are comfortable in a temperature range of 50 to 77 degrees Fahrenheit but cannot tolerate temperatures above that.
Please keep them away from direct heat sources, such as radiators or heaters.
Flower buds will fall off if the temperature drops below 41 degrees Fahrenheit, so low temperatures are also not ideal.
Even if they’ve grown and turned into buds, the cold can keep them from opening, so be careful.
It doesn’t like heat and humidity, but if it’s too dry, the flower buds and buds will fall off.
From October, flower buds will appear and gradually grow.
If the soil has been dry for over two or three days, give them a deep soaking.
From December through March, the plant is dormant and requires little to no water.
When Watering in The Cold, Use Caution!

If you water too much when it’s cold, the roots will rot, and the Christmas cactus won’t make it through the winter. Because of this, you can water plants infrequently.
However, if you don’t need water until the soil becomes hard, the Christmas cactus’s stem nodes will become wrinkled and weak, the flower buds will fall off, and the worst-case scenario is that the plant will die.
In the middle of summer, if you water in the morning, the soil temperature will rise during the day, which will stress the roots.
So instead, water in the evening, after the sun has set and the temperature has dropped.
As the water temperature in the soil drops at night during the winter, watering in the evening can be stressful for the plant’s roots.
Be careful not to stress the roots, or the flower buds will fall off.
Can I Make A Christmas Cactus Bud Bloom?

For cactus flowers to open, it is necessary to keep the flower buds attached, prevent them from falling off, and encourage the growth of enormous flower buds.
It is crucial, to begin with, post-flowering maintenance to guarantee the healthy development of the flower buds.
After the flowers have completed blooming in April through October, it is crucial to maintain them in the sun, where the temperature stays around 68 degrees Fahrenheit.
They will flourish if you expose them to early morning sunlight.
It would help if you protected them from the harsh midday sun by keeping them in a cool, shady spot where they won’t be exposed for long.
Without adequate light and air circulation, plants struggle to thrive and are more susceptible to diseases and pests.
Bring Your Christmas Cactus Inside Before The First Frost!
You should move the plant indoors for the winter before frost threatens it.
Put them on a windowsill or other sunny spot, but be careful of the temperature. In the fall, pinch off the leaves to limit growth and prepare the plant for blooming buds with a short-day treatment.
After you take off the leaves, you’ll need to water and adjust the fertilizers to stop the growth of flower buds, not shoots. Flower buds also need short-day treatment.
Pick the flowers as they wilt, and you’ll be rewarded with a steady stream of new blooms.
Picking flowers is simple; pinch and twist the stem at its base.
It’s best to pick the wilted flowers off the plant as soon as possible before they attract insects or develop mold.
What Is The Short-Day Treatment Method For Cacti?
As the flower buds grow in October, we can trick the cacti into getting ready to bloom by limiting their exposure to light to 12 hours a day or less.
The flowers will start to bloom in about a month.
For the short-day treatment to work, you’ll need to keep the container out of direct light and either cover it entirely with a cardboard box or store it somewhere dark.
Get a used cardboard box one size larger than the cactus’s dimensions (you may find these boxes for free at supermarkets and home improvement centers).
Apply duct tape along the seam of one side of the cardboard to seal any potential holes.
Reinforce the other opening’s four corners with duct tape so it won’t topple over when it’s covered.
If you put a black cloth or plastic bag over the cardboard, hardly any light will go through.
Short-day plants will detect light as not only sunlight but also indoor lights.
Since the cactus will be kept inside during the winter, be careful with the lighting in the room.
To achieve the best results from short-day treatment, it is essential to expose the plants to bright light during the day and darken the room once the sun goes down.
Key Takeaways
The cactus is a short-day plant that blooms when daylight hours are cut to 12 hours or less. If you do a process called “short-day treatment,” it will grow many beautiful flowers.
Short-day plants are ready to bloom by opening their flower buds when winter comes.
If you don’t give them short-day treatment, they won’t produce many blooms, and the ones they make will be tiny.
It takes about a month, but I hope you’ll give it a shot.