Kalanchoe After Flowering: Rest, Long Nights and Reblooming

The florist kalanchoe (Kalanchoe blossfeldiana) is often thrown away once its flowers fade. It doesn’t have to be. Iowa State University Extension says plants can be saved and forced to rebloom. It also admits the process is difficult for some home gardeners.

None of the extension guidance we checked calls for a dormant period. Instead, the year after flowering has two phases. The plant spends spring and summer growing new leaves and stems. In autumn, long nights trigger new flower buds.

Is your kalanchoe resting or in trouble?

A kalanchoe that has stopped flowering but has firm, green leaves is simply between bloom cycles. It is not dormant or dying.

Look for problems if you see:

• Soft, dark stems at the base, or yellowing in wet mix. Clemson Cooperative Extension says over-watering can damage kalanchoe. Root rot comes from mix that drains slowly or from watering too often.
• Long, weak, stretched stems. NC State’s florist kalanchoe profile asks for 6 to 8 hours of bright light a day. Iowa State says low light is the typical cause of spindly houseplant growth.
• Pests. NC State lists aphids, mealybugs and spider mites. Clemson adds brown scale.

Step 1: Right after flowering

The Clemson kalanchoe factsheet gives these steps for after flowering:

1. Cut back tall growth and old flower stems.
2. Move up one pot size. Shift the plant to a slightly larger pot.
3. Use a fast-draining mix. Clemson suggests well-drained, well-aerated mix, such as 60% peat moss and 40% perlite. NC State suggests a cactus or succulent mix.

NC State notes that deadheading spent flowers encourages more blooms. Remove faded flower clusters while the plant is still in bloom.

Step 2: Spring and summer growth

This is the “rest” period people ask about. In practice, it is a growing period.

• Light: Clemson says kalanchoe grows best in full sun and tolerates bright indoor light well. NC State prefers bright, indirect light and warns that long periods of direct sun can scorch leaves, so give afternoon shade.
• Outdoors: Clemson suggests moving the plant outdoors to a bright, lightly shaded spot for summer once frost danger has passed. NC State advises bringing it in before temperatures drop to 7 °C (45 °F).
• Water: let the mix dry slightly between waterings. Iowa State says dry, but not to the point of wilting. Never let the pot stand in water.
• Feed: Clemson advises feeding actively growing plants once a month with any houseplant fertilizer.

Step 3: Long nights to set flower buds

Kalanchoe is a short-day plant. Clemson and Iowa State both say it needs short days, meaning long nights, to form flower buds.

What the plant needs:

Factor	Guidance	Source
Night length	14 hours of darkness; natural winter nights give 14–16 hours	Iowa State, Clemson, NC State
Duration	About six weeks	Clemson, Iowa State, NC State
Start	October	Iowa State, Clemson
Day temperature	18–21 °C (65–70 °F)	Iowa State
Night temperature	16–18 °C (60–65 °F)	Iowa State
Heat limit	Above 27 °C (80 °F) during the long-night period can delay flowering	Clemson

How to do it:

1. From October, keep the plant in a room where lights are not turned on at night. Iowa State and Clemson both give this advice. The plant should get only natural light during the day.
2. Or control the dark yourself. Clemson suggests placing the plant in a closet in late afternoon and bringing it back out to bright light in the morning.
3. Keep it cool. Avoid heat sources during the long-night period.
4. Stop once buds show. Clemson says that once buds are large enough to be seen above the foliage, day length no longer matters. Put the plant anywhere.

Clemson says plants exposed to naturally short days in early October should begin flowering by January. That’s about 12 weeks from the start of long nights.

If it still won’t flower

NC State says a kalanchoe that fails to bloom has probably not had the period of darkness it needs to reset its bloom cycle. Check for:

• a lamp or other light reaching the plant during its dark hours
• a warm room during the long-night weeks
• too little light during the day

Iowa State’s houseplant diagnosis guide adds a few more checks for plants that won’t flower. Not enough light, too little fertilizer during spring and summer, or too much fertilizer can all reduce blooming.

Pets and children

NC State warns that florist kalanchoe is toxic if eaten. Keep it out of reach of children, dogs and cats.

For other kalanchoe types and a short reblooming summary, see kalanchoe varieties.

Related guides

Other kalanchoe problems we cover: overwatering, leggy growth.

References

• Clemson Cooperative Extension: Kalanchoe (HGIC 1563)
• Iowa State University Extension: How do I care for Kalanchoe?
• NC State Extension Gardener Plant Toolbox: Kalanchoe blossfeldiana
• Iowa State University Extension: Diagnosing Houseplant Problems from Improper Environmental Conditions