Kalanchoe

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Give it 2-6 hours of morning sun and shade by afternoon, and it has its best shot at blooming again. Back from a window it gets by, though in low light it turns spindly and likely won’t rebloom.

It sets flower buds only when nights grow long, so darkness and daylight together decide whether it blooms again. By day it wants strong light, and NC State puts its bloom budget at 6-8 hours daily.

An east window suits it best: it catches the gentle early sun, then falls into shade by midday. A south or west window works too if a sheer softens the afternoon, since long afternoon spells of sun on its thick, glossy leaves can scorch them.

A Chicago day in late December holds only about nine hours of daylight, so a winter kalanchoe needs nearly all of it to meet that budget. The sunniest sill you own is where its buds stand the best chance.

About every 10-14 days in summer and 2-3 weeks in winter, with the pot drying out between. Its thick leaves bank water, so a delay costs little; constant wet is what rots the roots and stems.

Pot it in a cactus or succulent mix (NC State), which lets a deep drink pass through rather than linger around the base.

For a flowering plant, it’s unusually content with dry indoor air: NC State notes low humidity suits kalanchoes, so a radiator-warmed Chicago apartment is no hardship. Its fleshy leaves don’t ask for misting, and NC State’s guard against powdery mildew is simply good airflow around the plant.

Gone for a while? Three weeks is fine if it’s watered the day you leave; pull it back from a hot window first.

A compact, branching mound of scalloped leaves that slowly reaches 6-18 inches tall and up to a foot wide, with flower clusters held above. Snip off faded flower stalks to coax more blooms.

Growers breed cultivars for compact, free-⁠branching form: Danish and Dutch breeders select plants that branch freely and flower heavily, then copy each winner from cuttings (US plant patents).

Each bloom is under half an inch across, yet packed into domes they hold color about four weeks (NC State). That makes one pot the centerpiece and the bouquet at once: set it mid-table where guests sit, and the flowers stay below their sightline.

It can summer on a porch or patio if it’s back inside before nights dip to 45°F (NC State).

A nibble may bring on vomiting or diarrhea in a dog or cat, and it passes on its own. For kids, the children’s poison center at CHOP lists it as non-⁠poisonous.

It carries heart-active compounds, but heart rhythm changes in pets are rare and take eating a large amount.

Its compounds turn up in every part of the plant and are most concentrated in the flowers (University of Illinois Extension). That makes a fallen bloom the likeliest snack, and the easiest one to tidy away.

For a child, a taste is nothing to worry about (CHOP). If a pet’s stomach doesn’t settle, or anything worries you, your vet or the ASPCA Animal Poison Control Center can help (a fee may apply). For a child, Poison Control can help.

To keep one with a curious cat or dog, pinch spent flower heads straight into the trash and give it a sunny sill they can’t reach. Its compact mound fits a narrow ledge or a window in a room the pets rarely visit.

1. ASPCA: mild for dogs (rates the whole genus).
2. Merck Veterinary Manual: toxic for dogs (rates the whole genus).
3. Pet Poison Helpline: mild for dogs (rates the whole genus).
4. ASPCA: mild for cats (rates the whole genus).
5. Merck Veterinary Manual: toxic for cats (rates the whole genus).
6. Pet Poison Helpline: mild for cats (rates the whole genus).
7. CHOP: safe for kids.

Cats and dogs: Most of the leading sources agree.

Kids: CHOP lists it as non-⁠poisonous.

Happiest at 60-70°F, and it shouldn’t sit below 45°F. Humidity can drop to 10% without trouble.

Temperature

60-70°F

Mealybugs hide in leaf axils and stem joints, and aphids cluster on new shoot tips and flower buds. Brown scale sits on stems and along leaf veins, and spider mites live under the leaves. Flip a few leaves to look.

• Mealybugs
• Aphids
• Brown scale
• Spider mites

A few. Mealybugs and aphids are the usual ones, then scale, and rot if the soil stays wet.

Mealybugs look like tufts of white cotton where the leaves meet the stem. Wipe them off with a cotton swab dipped in rubbing alcohol, then check again next week.

Aphids cluster on new growth and flower buds, small, soft and green or black. Rinse them off under the tap, or wipe them away with the same swab. Scale looks like small brown bumps; lift them off with a fingernail.

Powdery mildew is easy to miss on kalanchoe: only a fine, web-like film forms on the leaves. Pinch off the affected leaves and keep water off the rest. Stems going soft and dark at the soil mean rot from wet soil; see Troubleshooting.

Quarter-turn it toward the window each month and feed monthly in spring and summer. Pinch stems twice a year and deadhead spent blooms. After flowering, prune and repot. For rebloom, closet it 6 weeks in fall-⁠winter.

• Feed6× a year
• Deadhead3× a year
• Prune1× a year
• Pinch2× a year
• Repot1× a year
• Short-day rebloom treatment42× a year
• Rotate12× a year

A cactus or succulent mix, in a snug pot with a drainage hole.

Repot only when the roots fill the pot, once it has finished flowering, into a pot one size up.

Food helps it grow and bloom again: a houseplant fertilizer once a month while it’s actively growing, and none while it’s setting buds or resting.

Scalloped green leaves with a glossy, waxy finish crowd together and cover the soil. Domed clusters of tiny red, pink, or orange flowers rise above them and last for weeks.