Houseplant · Cactaceae
Christmas Cactus
Schlumbergera × buckleyi
Give it bright, indirect light and cool fall nights, and this old houseplant blooms right on cue for the holidays.
Bright indirect
55–81°F · 13–27°C
USDA 10–12
6–12 in · 15–30 cm
Overview
The Christmas cactus is a forest cactus, not a desert one. It grows wild in the trees of the Brazilian rainforest, perched on branches with its roots in pockets of leaf litter, which is why it wants steadier moisture than the spiny cacti most people picture. Indoors it stays small and lives for decades, often passed down from one gardener to the next.
What sets it apart is the timing of its flowers. As the days shorten and nights turn cool in fall, the plant takes the cue and sets buds, opening into arching, tubular blooms in pink, red, white, or coral right around the holidays. The flat, jointed segments give it a soft, cascading shape that suits a hanging basket or the edge of a shelf.
It asks for little once you understand that one trick about light and cool nights. Keep it in bright, indirect light, water when the top of the mix dries, and resist the urge to fuss over it. A plant left slightly pot-bound and undisturbed is the one that flowers best.
Care
The short version: bright, indirect light, water once the top of the mix dries, and a stretch of cool nights with long, unbroken darkness in fall to set the buds.
Light
Give it bright, indirect light through most of the year. It also gets by in medium light or light shade, but harsh direct sun in summer scorches the segments and tints them red. An east or shaded west window suits it well.
Water
Water when the top half of the mix dries out, then water thoroughly. This is a forest cactus, so it likes more moisture than a desert cactus but never sits in soggy soil. Once buds appear, keep the mix evenly moist, since a dry spell at that point makes the buds drop.
Soil
Plant it in a well-drained, organic-rich potting mix, the kind sold for cacti or succulents loosened with a little extra grit. A pH between 5.5 and 7.0 suits it. Drainage matters most here, because standing water at the roots is what kills these plants.
Temperature
Ordinary room warmth between 55°F and 81°F (13°C to 27°C) keeps it happy through the year. The exception comes in fall, when cool nights around 55°F to 60°F (13°C to 16°C) are part of what triggers blooming.
Humidity
Average household humidity is plenty, so there's no number to chase. As a rainforest plant it appreciates a bit more moisture in the air, and grouping it with other plants or setting it on a pebble tray covers that without any trouble.
Feeding
Feed monthly through spring and summer while it's growing, using a balanced houseplant fertilizer at half strength. Stop by late summer to nudge it toward fall flowering, and switch to a low-nitrogen, high-phosphorus feed as bloom season nears.
Pruning
After it flowers in spring, pinch or twist off a few end segments to push the plant into branching and fill out bushier. The pieces you remove aren't waste, since they root readily into new plants.
Repotting
Repot only every 3 to 4 years, and don't rush it. This cactus blooms best when left slightly pot-bound, so a too-roomy pot gives you more leaves and fewer flowers. Roots creeping from the drainage holes or soil that dries almost at once tell you it's finally time.
Size & spacing
A mature plant stays compact at 6 to 12 inches (15 to 30 cm) tall but can spread 12 to 24 inches (30 to 61 cm) wide as the jointed stems arch and trail. That cascading habit makes it a natural for a hanging basket or a high shelf.
Troubleshooting
Most Christmas cactus trouble comes down to water, light, or the conditions it needs to bloom. The plant tells you plainly through dropped buds, soft stems, or color in the segments. Match what you see below and adjust before a small slip turns into a lost season.
Limp, mushy stems above soil that won't dry out
When a plant wilts even though the soil is wet, the cause is root rot from too much water or a heavy mix that holds it. Check the roots, and if they're brown and soft rather than firm and white, let the plant dry out and repot it into fresh, fast-draining mix with the rotted roots trimmed off. Tip out any saucer so the pot never sits in standing water.
Fix:
- Allow the plant to dry out
- Repot into a fresh, fast-draining mix and trim away rotted roots
- Empty saucers so the pot never stands in water
Buds yellow and drop before they open
Bud drop almost always traces back to a sudden change once the buds have set, whether a cold draft, a warm vent, or a missed watering. Keep the plant in one steady spot and the soil evenly moist while it's in bud. Don't move or even rotate it, since the plant resents being shuffled around right before it blooms.
Fix:
- Keep the plant in a stable spot away from heat vents and cold drafts
- Keep the growing medium evenly moist once buds appear
- Avoid moving or rotating the plant while in bud
Healthy plant that simply won't flower
A plant that won't bloom is usually one kept too warm and too brightly lit through fall. Buds form only after a stretch of cool nights around 55°F to 65°F (13°C to 18°C) paired with 12 or more hours of unbroken darkness each night for about 6 weeks. Even a lamp switched on during that dark spell can stop the flowers from setting.
Fix:
- Provide cool nights of about 55 to 65°F
- Give 12 or more hours of continuous darkness each night for roughly 6 weeks starting in fall
- Avoid interrupting the dark period with artificial light
Stem segments tinged yellow or red
Segments that flush yellow or red are sunburned from too much direct light, most often during summer. Move the plant into bright, indirect light and give it some shade through the hottest months. The color usually settles once the harsh sun is off the leaves.
Fix:
- Move the plant to bright, indirect light
- Provide light shade during hot summer months
Toxicity
Good news for pet owners: the Christmas cactus is safe. The ASPCA lists it as non-toxic to cats and dogs, and it holds no poison that threatens other animals or people. A pet that chews a lot of the fibrous stems might get a brief, mild stomach upset, but that's the extent of it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Safe to share a home with a cat. A cat that gnaws a lot of the fibrous stems might get a brief bout of vomiting or loose stool, but the plant holds no toxin.
Dogs None
No poison here for dogs. If a dog tears into the stems and swallows a big mouthful, the worst you'll likely see is some short-lived stomach upset that clears on its own.
Horses None
Nothing in this plant is toxic to horses, and its small indoor size keeps it well out of a horse's reach anyway.
Rabbits None
A rabbit can nibble the segments without harm. As with any fibrous green, a very large helping might loosen the gut for a day, but it carries no danger.
Livestock None
Free of any toxin that troubles goats, sheep, or cattle. As a houseplant it rarely crosses paths with farm animals in the first place.
Birds None
Pet birds face no poisoning risk from the stems or flowers, so a stray peck is nothing to worry about.
People None
Not poisonous to people, including young children. It isn't grown to eat, so there's no reason to taste it, but a curious bite won't do harm.
Varieties
Three holiday cacti turn up under the same name, and telling them apart comes down to segment shape and when they flower. These are the ones you'll run into.
Thanksgiving cactus (Schlumbergera truncata)
Its stem segments carry pointed, claw-like teeth along the edges and it blooms near Thanksgiving, and most plants sold as Christmas cactus are really this species.
True Christmas cactus (Schlumbergera × buckleyi)
This one has rounded, scalloped segment margins and a drooping habit, and it flowers closer to Christmas than its earlier cousin.
Easter cactus (Rhipsalidopsis / Hatiora gaertneri)
A separate genus altogether, with rounded segments edged in small bristles and flowers that open in spring.
How to propagate
Few houseplants are easier to copy. A twisted-off piece of stem roots on its own with hardly any effort, which is how most of these plants get handed around.
Stem cuttingsEasy
Late spring to early summer after flowering (about May to June) · Roots form in about 2 to 8 weeks
Take cuttings in late spring to early summer once the plant has finished flowering, around May to June. Twist off a cutting of 2 to 5 joined segments, let the cut end callus over for a day, then press it into a moist, well-draining mix. The segments root with little fuss in about 2 to 8 weeks, and a humidity cover speeds things along.
Myths
The three holiday cacti are the same plant, so segment shape and bloom time do not matter.
They really are different plants, and you tell them apart by segment shape and when they flower. Thanksgiving cactus has pointed, claw-like teeth on its segments and blooms in late November, true Christmas cactus has rounded, scalloped margins and opens closer to Christmas, and Easter cactus is a separate genus that waits until spring. Most plants sold as Christmas cactus are actually Thanksgiving cactus.