Houseplant · Crassulaceae
Flaming Katy
Kalanchoe blossfeldiana
Hand it bright light, gritty soil, and dry spells between waterings, and this succulent fires off weeks of bloom.
Bright indirect
59–77°F · 15–25°C
USDA 10–12
6–12 in · 15–30 cm
Overview
Flaming katy is a small Madagascan succulent that earns its spot with long-lasting clusters of bright flowers. It runs with jade and sedum in the same family, packing water away in thick, glossy leaves just like they do. Forget a watering and it shrugs, but tip too much in and it rots fast, so growing it well means leaning dry.
Most plants top out at just 6 to 12 inches (15 to 30 cm) tall, slotting onto a windowsill with room to spare. The flowers blaze in red, orange, pink, yellow, and white, and a single flush holds that color for weeks on end. Florists push it into bloom year-round, which lands it on gift tables in every season.
Keeping it alive is a breeze, and getting it to flower again is the rewarding part once the trick clicks. Feed it bright light and a run of long nights to set buds, and let the soil dry out completely before the next drink. Crack those two and it reblooms year after year.
Care
The short version: bright indirect light, gritty fast-draining soil, and a deep soak only once the soil has dried out completely. Feed lightly through the growing season, then run long fall nights to fire it back into bloom.
Light
Set it in bright indirect light, like a perch near a sunny window that dodges the brutal midday rays. It handles some direct sun and even partial sun, but starve it of light and it stretches out and clams up on flowering.
Water
Let the soil dry out completely, then drench it through and dump whatever pools in the saucer. This succulent rots fast in soggy soil, so when in doubt, hold off. To fire it back into flower it also wants about six weeks of long nights, roughly 14 hours of uninterrupted darkness.
Soil
Pot it in a gritty, well-drained mix that water blasts straight through, like a cactus blend. A slightly acidic pH of 6.0 to 6.5 suits it, and that sharp drainage is what keeps the roots out of trouble.
Temperature
Ordinary room warmth keeps it humming, ideally 59°F to 77°F (15°C to 25°C). Steer it clear of cold drafts and frost, since this tender plant will not take a chill.
Humidity
Average household air does the job, and it thrives on the low side of humidity. No number to chase here, and dry indoor air beats a steamy bathroom every time.
Feeding
Feed it monthly through spring and summer while it is charging ahead, with a balanced water-soluble fertilizer diluted to half strength. Pull back in fall and winter as growth eases off.
Pruning
Deadhead the spent blooms to keep it sharp, then pinch the stems back after flowering. That drives bushy, compact growth instead of a handful of long, bare stalks.
Repotting
Bump it up a pot size every 1 to 2 years, or sooner if it crowds, always grabbing a container with drainage. Roots punching through the holes, water rushing straight through, or stalled growth all shout that it is time.
Size & spacing
Look for a compact plant of 6 to 12 inches (15 to 30 cm) tall spreading 8 to 16 inches (20 to 40 cm) wide. Give it room for air to whip around the leaves, which helps fend off powdery mildew.
Troubleshooting
Chase almost any flaming katy hiccup and it lands on water or light. Pour on too much and the roots rot, starve it of light and it stretches out, shy of flowers. Match the symptom below and go straight for the cause, not just the surface.
Soft, blackening stems and a collapsing base
Catch a soft, blackening base early and you can turn it around, because this is root and crown rot that springs from too much water in soil that holds it. Slide the plant out and look: brown, soft, smelly roots tell the tale where firm pale ones should be. Cut away every rotted scrap with clean tools, repot into fresh gritty mix, and hold the water until it bounces back. Switch to a draining pot and dry the soil out fully each time, and the rot loses its grip for good.
Fix:
- Remove the plant from wet soil
- Cut away all rotted tissue with clean tools
- Repot into fresh gritty, well-drained mix
- Withhold water until the plant recovers
Stretched, leggy growth begging for blooms
Leaning growth with wide leaf gaps is the plant reaching for more light, and a no-show second bloom means it never got the long nights that fire up its buds. Both are an easy win. Shift it into a bright spot with indirect light, then hand it about six weeks of roughly 14 hours of complete darkness each night to spark budding, and pinch those leggy stems back to rebuild the shape. Keep the light coming all year and run a controlled short-day spell each fall, and it flowers on cue.
Fix:
- Move to a bright spot with indirect light
- Provide about six weeks of roughly 14 hours of complete darkness each night to trigger budding
- Pinch back leggy stems
White, powdery patches creeping over the leaves
A pale, dusty coating that rubs right off the leaves is powdery mildew, and it pounces on crowded plants stuck in still, humid air. Strip off the worst leaves first, then spread things out so air rushes through and stop splashing the foliage when you water. Aim the water at the soil line and keep the humidity low, and it stays gone.
Fix:
- Remove badly affected leaves
- Improve air circulation and spacing
- Avoid wetting the foliage when watering
Toxicity
Respect this one around animals, because it packs a real punch. Every part holds bufadienolides, cardiac glycosides that churn up the gut and, in larger amounts, knock the heartbeat off track. Keep it clear of pets and livestock, and call a vet right away if an animal eats any of it.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that chews any part will likely start drooling, vomiting, and running to the litter box before long. A bigger bite can rattle the heart rhythm, so jump on it fast.
Dogs Toxic
Drooling, vomiting, diarrhea, and a dog gone sluggish are the tells. Down a big mouthful and the same bufadienolides can slow or skip the heartbeat, so act quickly.
Horses Toxic
The cardiac glycosides charge through the whole plant, so a horse that grazes on it risks colic, diarrhea, and a dangerous heart arrhythmia.
Rabbits Toxic
Skip it entirely with a rabbit, because no amount is safe. Even a few leaves can kick off gut upset and the heart-rhythm trouble these glycosides cause.
Livestock Toxic
Cattle, goats, and sheep that get into it can wind up drooling, scouring, weak, and beating out an irregular rhythm, all from the bufadienolides.
Birds Toxic
Park it well out of reach of birds. The same cardiac toxin hits them too, and their small size means even a little does harm.
People Caution
Nobody should snack on this plant, since swallowing it can upset the stomach. Keep it clear of small children who might want to taste the bright flowers.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Most flaming katy on the bench today has been bred for fuller flowers and a tight, compact shape. These two groups cover what waits at the garden center.
Calandiva series
These compact plants pack fully double, rose-like flowers across a sweeping range of colors.
Flapjacks-flowered florist hybrids
These single-flowered florist forms crowd their stems with red, orange, pink, or yellow bloom.
How to propagate
Flaming katy multiplies with almost no effort, and one plant hands you a whole tray of starts. Root a stem tip or raise new plants from a single leaf, both best launched in spring or summer while it is growing strong.
Stem cuttingsEasy
Spring to summer during active growth · 2 to 3 weeks to root
Making more of this plant is a genuine treat, and a stem tip taken in spring or summer while it is growing is the fast track. Snip a healthy tip, let the cut end callus for a day or two so it will not rot, then plunge it into gritty, barely moist mix. It roots in about 2 to 3 weeks.
Leaf cuttingsModerate
Spring to summer · 3 to 6 weeks to form plantlets
Turning one leaf into a whole new plant never gets old, and spring or summer is the time to try it. Let the leaf callus, lay or stand it on well-drained mix, and keep it lightly moist while tiny plantlets push up at the base over 3 to 6 weeks.
Myths
It is a harmless gift plant that is safe around pets.
As cheery as it looks, this florist favorite is the real deal when it comes to toxicity for cats and dogs. Its bufadienolides are cardiac glycosides that trigger vomiting and diarrhea and, in quantity, can throw off the heartbeat. Grow it gladly, just keep it up and out of reach rather than treating it as a worry-free houseplant.