Ah, the Christmas Cactus (Schlumbergera bridgesii) , the plant most beloved by little old ladies all over the world, probably because they’re the only ones that can make it actually bloom. The rest of us just watch them grow and shed blooms because we’ve angered it in some way.
Quickfire Christmas Cactus care
- Light: bright, indirect
- Humidity: 50%-60%
- Temperature: room temperature, with a drop in winter to promote blooming
- Watering: bottom water, water when moisture metre reads 2
- Fertilise: 20-20-20 every 6 weeks in summer
- Potting medium: cactus mix, or house plant mix with perlite
- Propagation: Stem cuttings
- Pests: mealybugs, scale
- Bloom? yes
- Toxic? no
Where do Christmas Cacti come from?
They come from Brazil, and are actually epiphytes, believe it or not. They live in the rainforest and grow non-parasitically on trees.
Where should I put my Christmas Cacti?
Christmas cacti are best placed in a east or north-facing window, where the light they receive will most mimic their natural environment.
Once your plant has produced flower buds, you need to put it somewhere where it receives less light, so have a spot ready for it if you’re after those spectacular flowers.
That being said, if you think you need to move the plant for the good of its health, do so, but don’t be surprised if it has a little tantrum and refuses to bloom.
What light conditions do Christmas Cacti like?
Christmas Cacti like bright, indirect light, but they can hack a little direct light. An east-facing windowsill is perfect. I know that most cacti require a lot of bright light, but since Christmas Cacti live in the rainforest, they wouldn’t be exposed to direct light for much of the day.
You can absolutely grow Christmas cacti under grow lights, which might be the best option for you if you don’t have a suitable place near a window to put your cactus.
How humid do Christmas Cacti like their environment?
This links to the grow light bit above – since they’re native to the rainforest, Christmas cacti do appreciate a higher level of humidity than, you know, normal cacti.
Ideally, we’re looking at around 50-60%. If you want blooms, you’d be best off getting a humidifier if your home is less humid than this.
What temperature do Christmas Cactus prefer?
Ooo, it depends. They’re pretty happy with regular room temperature in the UK, so 20-24 C in summer (68-75F), but if you want blooms, then they require a drop in temperature in wintertime, but I’ll discuss that in the flowering section.
How to water a Christmas Cactus
Like regular cacti, Christmas cacti is susceptible to rot BUT they don’t like to dry out to the same degree as other cacti, so I would recommend bottom watering.
Use a moisture metre (or your finger) and water your plant thoroughly when the moisture metre is at about the ‘2’ mark, or when the top inch of soil is dry.
If your plant is in a terracotta pot, I like to really soak the pot (usually by filling the bath to about six inches deep and putting a load of pots in) because the pot will soak up a lot of moisture.
It can be a real ballache using terracotta pots because you have to water more often, but you can dramatically decrease the chance of root rot.
How to fertilise a Christmas Cactus
Ok, listen up, because you don’t fertilise cacti when you’d think.
Cacti in generally bloom when it’s cold, and outside of the active growing period. I know, I know, technically they’re growing when they’re blooming, but they’re not really.
So, fertilise your Christmas cactus in the growing season, typically the end of March to October, depending on when you live.
The short days and cool weather make your plant bloom. Lack of light, and food. Don’t fertilise when it’s blooming, it won’t help.
When it comes to which fertiliser to use, look for a 20-20-20 formula (use at half-strength, monthly or every 6 weeks), or one that’s a little higher in phosphorus to help the blooms.
Once late summer comes around, stop fertilising so that the flowers will start to form.
Pests common to Christmas Cacti
Potting mix for Christmas Cactus
It’s recommended that you pot your Christmas cactus in a half and half mix of regular house plant potting mix and perlite. Alternatively, I’m sure a specific cactus mix would do the job but may require you to water more often.
What type of pot do Christmas Cacti like?
I like to pot all my cacti in terracotta, just because they are so susceptible to root rot. To be honest, they’re probably not fussy, so as long as they have a drainage hole, they’ll be fine.
Are Christmas Cacti toxic?
Christmas cactus have been classified as non-toxic by the ASPCA.
How to propagate Christmas Cacti
I’ve never tried, but apparently it’s super easy.
- Cut a ‘branch’ off your cactus – a Y-shaped segment – we’re looking for about three joined segments.
- Let the cutting sot for a few hours, so that it callouses over. Excess moisture at the wound can cause stem rot
- Put about a quarter of the cutting in a moist cactus potting mix.
- Water sparingly
- You should see growth in a couple of weeks
- (It’s best to try propagating just after a plant has bloomed)
Tips on Christmas cactus blooms
- Once your plant has buds, move it out of direct sunlight
- Make sure your cactus has 12 hours of darkness so it knows it’s blooming time
- Keep your plant cool – 10C/50F
- Reduce the amount of watering
- Keep your plants out of any draughts, because draughts can cause buds to drop off
What we’re trying to do is tell the plant it’s winter. Which means those of us that have cold winters don’t have to do much to convince our Christmas cactus to bloom but those of you in hot countries have your work cut out for you.
- Despite me thinking that easter and Christmas cactus are the same, they’re, er, completely different plants, but require similar care.
- Thanksgiving cactus is different again
- Thanksgiving cactus is Schlumgera truncata
- Christmas cactus is Schlumgera bridgesii
- Easter cactus is Rhipsalidopsis gaertnerii
- So now you know.
- They quite like to be, if not root bound, quite compact in the pot
Troubleshooting Christmas Cactus
Why won’t my Christmas cactus bloom?
Chances are, it’s getting too much light. It’s important to give your CC 12 hour of darkness, so you can’t keep it in a room where the lights are on late at night.
By keeping the plant in a room that, er, you’re in, it’ll probably be in cool enough temperatures to force it to bloom
Why are the buds on my Christmas cactus dropping off?
- There’s been a sharp drop in temperature
- It’s sat in a draught
- The room is too humid or isn’t humid enough. For a Christmas cactus to bloom, it needs to think it’s winter, and winter ain’t humid. But it also doesn’t want bone-dry air.
- It has too many buds. Fair enough. It knows what it can handle.
- You moved it and it didn’t like it.
- Incongruent watering. Get a moisture metre. You’ll thank me.
Why did my Christmas Cactus die?
From my research, I can conclude that Christmas cactus can get root rot really easily, so chances are it’s probably that. Or you neglected it and it dried out.
Also, check it for mealybugs.
I HAVE QUESTIONS
How do these things bloom in the wild? Winters in Brazil aren’t cold, surely, and the days are long. There’s no 12 hours of darkness. Do they only bloom in captivity?
EDIT: apparently there ARE long nights in Brazil. Never mind. It’s not cold though, is it? Am I thinking of a different Brazil?