Poinsettia, start right now to make it turn red again

Make poinsettia red

Poinsettia gets all the votes at Christmas, since red and green match the colors of the party! After the season is over, one question remains: how can you get it to turn red?

Poinsettia, or “Christmas star”, invades garden stores from now until the end of the year. Its appeal lies in the famous colored bracts that surround its tiny flowers.

The challenge? Make your poinsettia turn red again year after year!

How to make poinsettia red again

How to turn poinsettia red again Colored leaves appear during days with short daylight hours. This means it needs less sunlight and more darkness.

It takes 2 months for these new red leaves to form, so plan ahead:

1/ Start the poinsettia’s “sunlight diet” in September (mid or end).

2/ Keep rationing light through October and November.

3/ It’ll get red leaves around Christmas and New Years.

How much darkness should it get?

For maximum color on new leaves, make sure your poinsettia gets 14 to 15 hours of complete darkness every day.

Stick to the routine day in and day out, ideally always at the same time of day. You’re imitating the continuous, long winter nights from its native Mexico wilderness.

  • For example, 6:00 PM to 8:00 AM is 14 hours. (18:00 → 08:00)
  • 5:30 PM to 8:30 AM is 15 hours (17:30 → 08:30)

Practically, you’ve got two ways to get this done:

  • Option 1: Shuffle the plant around – During the day, put it in a brightly lit spot (natural light is best). For night-time, move the poinsettia to a spacey closet.
  • Option 2: Cover it at night – Keep the plant in the same (bright) spot, but cover it up with a carton that blocks out light completely. It must be pitch-dark underneath.

Make poinsettia flower againDuring this “light diet”, try to keep cooler temperatures during the nighttime, around 60 to 65°F (15 to 18°C). Water normally: this is still a growth phase for the plant. It isn’t yet dormant and needs regular watering.

Once the eight weeks are over, no need to control its light intake anymore. And it will flower again – most certainly! – at Christmas.

Don’t throw your poinsettia away!

Poinsettia grows in the wild in Mexico where it easily reaches six feet (two meters) tall. In temperate climates, it grows much smaller, making it ideal for decorating tables.

Red is most common, but some are pink, salmon orange, yellow,cream,white,mottled… They all have bright green leaves as a backdrop.

Too often, poinsettia has a sad fate once the party is over… and ends up in the trash (or, slightly better, the compost pile…)!

Caring for poinsettia after the bloomingAfter the blooming, simply place it in a cool room and give it water at regular intervals. At the end of spring, reduce watering. When leaves start falling off, the plant is entering its dormant phase. As this occurs, let the soil dry up completely for a month. At the end of this phase, cut it back quite short, back to 4 inches (10 cm), and water to trigger a new vegetation phase. Place it in a warm spot.

Poinsettia appreciates surrounding temperature between 60 and 74°F (15 and 23°C) while avoiding hot, dry air and drafts. Proper moisture must be ensured (immerse the pot in water at room temperature, then drip excess water out without ever letting water accumulate in the saucer). Also give it a lot of light. You can bring the plant outdoors between May and September and feed it fertilizer over the summer.

Poinsettia after-blooming care, a summary:

  • January/February: Move your poinsettia to a cool but very bright room. Water regularly, not too much, until spring.
  • March: End of spring, stop watering to trigger leaf fall. Keep the soil dry for a full month.
  • May: Cut stems back to 4 inches/10 cm. Start watering again, fertilize and place in a warmer spot to trigger new leaves (even outdoors).
  • End September: start restricting light as described above.

→ Gardening: poinsettia care

Images: adobestock: New Africa; Pixabay: Peggy und Marco Lachmann-Anke, Andreas Lischka; Public Domain: Alabama Extension

Written by Gaspard Lorthiois | Loves helping out, especially when it comes to growing things. Worked in herbal medicine, runs a farm, and dabbles in tech. Master's degree and engineer.