One of the best things about Schlumbergera is its habit of blooming at times of the year when most of your other plants are dormant.
Of these, the Christmas cactus is perhaps the most popular. This wonderful succulent is easy to grow and propagate while providing beautiful blooms for the holidays.
That is when it wants to bloom. Sometimes getting this plant to truly shine is a little more complicated than general care.
But before you give up, let’s take a moment to look at why your beloved Christmas cactus isn’t flowering.
Why Isn’t My Christmas Cactus Blooming?
There are a few reasons your Christmas cactus refuses to bloom, and many revolve around telling your cactus it’s winter.
Here are the most common reasons and what to do about them.
One thing a lot of newer enthusiasts forget is that plants bloom when they mature.
Try to remember when you propagated your plant or when you purchased it.
Christmas cacti will only bloom when they’ve been growing for at least two years.
Disease or Infestation
It should come as no surprise that a visit from common Christmas cactus pests or diseases can affect more than looks.
Check for any signs of bugs on your plant, as well as discolored leaves or signs of root rot.
Dealing with these issues, especially early on, can help your plant feel healthier and encourage it to produce flowers.
Humans tend to harvest most of their food in the autumn, so it’s easy to forget that plants have the opposite feeding cycle.
In nature, winter is a time where organic matter breaks down and enriches the soil.
These nutrients have largely been used up by autumn, causing plants to go dormant until nature can replenish the soil again.
Christmas cacti pay attention to this cycle to help them know when it’s time to bloom.
By fertilizing in the autumn, you’re telling the plant it isn’t time yet, even though this is often a signal to other plants to start blooming.
Apply a general liquid houseplant fertilizer at half strength once per month in spring and early summer for best results.
Stop feeding around August to let the plant know the flowering season is on its way.
It might surprise you to know that your Christmas cactus has a sleep cycle.
- During the day, it loves bright, indirect light.
- However, it likes a bit more darkness at night.
- This is especially true around September when the plant will require dark at bedtime for around 12 hours per day.
- One way to ensure it gets a good night’s sleep is to move it to a room that can be closed off at night.
Another, easier method is to cover the plant with a cardboard box at night to block out any potential light.
If using a box, remember to cut some air holes along the bottom so the plant can breathe and enjoy ant breezes.
Some plants need plenty of room to stretch their toes (roots), but others like the Christmas cactus prefer something a bit cozier.
When transplanted into a larger pot, your cactus will focus on root growth, hoping to achieve that little bit of root binding that makes it feel nice and comfortable.
Think of it like wrapping yourself in a warm blanket on a cold day.
Keeping your Christmas cactus in a pot small enough to allow for slight root binding will make it feel safe, and the plant will begin putting its resources to growing in other areas – such as flowers.
What sets the Christmas cactus apart from its relatives is the timing of its blooms.
Sometimes a failure in blooming is just a case of mistaken identity.
Have a look at your plant’s leaves (a form of flat, segmented stem called cladophylls), as the shape will often tell you which holiday plant you have.
- Christmas Cactus (Schlumbergera x buckleyi) has flat, scalloped, or teardrop leaves.
- Easter cactus (Schlumbergera gaertneri) has curved scalloping.
- Thanksgiving cactus (Schlumbergera truncata) has spiny edges.
This article looks at the Difference between Easter Cactus and Christmas Cactus.
Just as you might, Christmas cacti prefer slightly cooler temperatures at night.
The ideal daytime temperature is around 68 to 70° degrees Fahrenheit.
In the evening, these temperatures should be between 60 and 65° degrees Fahrenheit.
In some cases, a bit of breeze can also help your cactus relax when you can’t lower the ambient temperature overnight.
Remember, your cactus needs to know when it’s winter, so reducing the temperatures around September to October to 55 to 60° degrees Fahrenheit at night can help encourage blooms.
Just be sure not to let drafts reduce the temperature below 50° degrees Fahrenheit or your plant might suffer damage.
Your Christmas cactus is adapted to a rainforest environment, so you’ll want to have a decent amount of ambient humidity, such as a pebble tray or humidifier.
You may also choose to mist occasionally.
However, it’s also important to remember that this plant is a succulent, so you should avoid overwatering.
Moisten the soil when it’s dry to the touch, approximately ½ to 1″ inch down.
Around September, cut back watering until the soil is dry, approximately 1.5″ inches down.
This will help encourage blooming as the drier period is another sign to the plant that winter’s coming.
You can return to the regular watering levels once blooming has ended.