When it comes to Christmas cactuses, there is one complaint I hear time and again: “I can never get mine to bloom.”
That’s understandable, considering these plants need special care to trigger bud development. It’s nothing difficult, and anyone can do it. But if you keep tending your Christmas cactus like you do every other houseplant, it’s unlikely you’ll get it to bloom.
What’s more, with one simple trick, you can kick your Christmas cactus into overdrive so that not only does it bloom, but it puts out tons of flowers year after year.
Getting Your Christmas Cactus to Bloom
Alright, first things first: How do you get the silly thing to bloom in the first place?
Holiday cactuses (Christmas, Thanksgiving and Easter – all named for the holiday they bloom closest to) are all short-day blooming plants. This means longer and cooler nights and shorter days trigger a period of dormancy in the plant, which leads to blossom development.
To get a Christmas cactus to bloom, you need to mimic these conditions in your home.
In the fall, about six weeks before Christmas or Thanksgiving (depending on which type of cactus you have), you’ll need to ensure your plant receives about 14 hours of darkness each day. It also needs to be kept in a cooler part of the house to mimic those cool outdoor temps. It can be helpful to move your plant somewhere inside your home that’s cooler than the rest of the house, such as a garage, pantry or the basement.
If you need to, you can cover the plant with a black sheet or a large cardboard box to simulate nighttime.
During this dormant period, do not fertilize the plant, and reduce the frequency with which you water it. You want to let the plant dry out to about the top two inches of soil before watering again, sparingly.
After about six weeks, the plant will begin to produce buds. As soon as you see buds on it, you can move it back to its normal spot in your home and resume normal care.
For a more in-depth look at these plants and how to care for them (and identify the different holiday cactuses), take a look at Christmas Cactus – How to ID & Care for Everyone’s Favorite Holiday Plant.
Now that you know how to get it to flower…
Let’s Get Your Christmas Cactus to Make TONS of Blooms
Okay, before I let you in on this simple trick, there is some bad news. (Don’t shoot the messenger.)
If you’re reading this article in the run-up to Christmas, it’s too late to do it this year. But you should keep reading anyway, as you’ll be able to implement this tip for the following year. Once you try it, you’re likely to do it every year. My mom always did, and her Christmas cactus was the envy of the family. So, here’s the tip.
Put your Christmas cactus outdoors for the summer. But do it carefully.
This is one plant you can’t just stick outside and forget about until fall rolls around. It’s important to wait until nighttime temperatures remain consistently above 55 degrees F (13C). Once the nights are predictably warm, you can move your Christmas cactus outdoors for the duration of the summer.
The right location is important. These tropical plants can’t handle the extremes of direct sunlight; otherwise, they will quickly burn.
My mom’s Christmas cactus was in a hanging basket, and she would hang it in her lilac bush for the summer. She would place it so the plant was on the east-facing side of the lilac; that way, it would get a nice, healthy dose of bright, early morning sun before it got too hot. By the time the sun was high enough to become damaging, the plant would be protected in the shade of the lilac yet still soaking up the light.
When fall arrived, and nighttime temperatures began to dip towards the cooler end of 50 degrees, Mom would bring the Christmas cactus in and put it on top of our big old chest freezer in the pantry. There was a small west-facing window on the door to the backyard in there, and that was the only light. It was cool, as the pantry also led down to the basement.
This created the perfect environment for the cactus to go into its dormant phase during the weeks of October and early November.
As soon as she found the first pink bud developing, the plant was moved to the living room, on its special plant stand by the window. By Thanksgiving, it was a riot of fuchsia blooms every single year.
When choosing a spot for your holiday cactus to hang out in the summer, keep a few things in mind.
Shelter
Thanksgiving and Christmas cacti both need lots of bright, diffused light. Pick a location where the plant won’t be blasted by direct sunlight. Be especially careful not to place it somewhere it will be in line with the heat of the afternoon sun. Check your plant often. If you see signs of sun damage (red or purple-tinged leaves), you’ll want to move it to a more sheltered location.
A sheltered location also protects the plant from summer storms. Being outdoors will help your plant grow a thicker, sturdier base, but violent summer storms can also tear apart the tender waterfall-like segments.
Water
It’s important to check on an outdoor houseplant frequently. This is especially important during hot spells when the soil can dry out quickly. During the summer, the plant will be in its active growing cycle. Water it as soon as the top inch of soil is dry. (I always do the knuckle test and stick my finger in the soil up to my first knuckle.)
Fertilizer
As well as energy from the sun, your plant needs nutrients. Feed your Christmas cactus with a balanced liquid plant food meant for houseplants. However, towards the end of the summer, a few weeks before you plan to bring your plant inside, switch to a fertilizer that’s specifically formulated for blooming plants. This is what I use.
This will give your cactus a boost of phosphorous, which is vital for bud formation. Stop fertilizing your holiday cactus once it goes into its ‘dark phase’ period of dormancy.
Related Reading: My Surprising Fertilizer For Stunning Christmas Cactus Blooms
Weather
It’s always a good idea to move your Christmas cactus somewhere sheltered if you’re expecting a storm. A protected porch or patio is a suitable spot. This will prevent soil from being splashed out of the pot from heavy downpours and protect the plant from heavy wind gusts. Once the storm is over, you can move your plant back to its summer home.
Cold Nighttime Temperatures
Always bring your plant back inside before temperatures get too cold. (Below 55F.) There’s nothing worse than forgetting about a plant outside, only to realize later it’s been damaged from the cold.
Depending on where you live and your climate, you may be able to time when you bring your plant in with the necessary dark, dormant phase it needs to trigger flowering. Often, the simple act of bringing it back into our darker homes can be enough.
Why It Works
Here’s the thing: it’s difficult to get a houseplant to thrive indoors. Oh sure, many of us are really good at keeping houseplants alive and looking good. However, it’s one thing to keep a plant moderately healthy in your home. It’s another to give it the conditions it needs to thrive.
Blooming plants require a ton of energy to produce blossoms. They get that energy from the sun.
The vast majority of houseplants, including Christmas cactuses, are tropical and need a lot of light to stay healthy. If you want them to bloom, then they need even more light. It can be difficult to provide the amount of light needed in our homes. We’re terrible at judging just how much light our plants are getting.
For comparison, on a sunny day, stand in the sunniest spot in your home. Now go outside.
Even with all the sun in your home, you’re always going to have more light outdoors.
The other thing you need to keep in mind is that blooming plants need a lot of light over a long period of time. Most of that energy produced from sunlight goes into their annual growth cycle. To ensure that your Christmas cactus has plenty of energy left for flowering, you need to give it lots of light for as long as you can.
Think of your Christmas cactus as a solar-powered battery. It needs to spend all summer soaking up energy and storing it for all those holiday blossoms. Letting your plant spend the summer outside is the best way to ensure you have a Christmas cactus that will be covered in flowers come the holidays.
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