How to Get Your Poinsettia to Turn Red Again Next Holiday Season

The brilliant red leaves of poinsettias are a sight to behold during the holiday season. But once Christmas is over, the red bracts fall off, leaving you with a regular green houseplant. If you want that pop of bright color back next holiday season, you can make your poinsettia turn red again with a little extra care. Here’s what you need to know.

Why Poinsettias Turn Red

Poinsettias are native to southern Mexico and Central America. In their natural habitat, the plants turn red or produce colorful bracts during the winter in response to the shorter days and longer nights.

As daylight hours decrease, poinsettias go through a physiological change that shifts them into a flowering state. The red color comes from specialized leaves called bracts that surround the tiny yellow flowers in the center of the plant. Getting poinsettias to turn red again involves replicating those short daylength conditions.

When to Start

To force your poinsettia to turn red, you need to manipulate the light exposure starting around early October. The plant has to receive at least 14 hours of uninterrupted darkness each night for about 8-10 weeks.

Start the treatment at least 8 weeks before you want the plant to turn fully red. It usually takes 4-6 weeks before you start seeing the leaves change color. Then allow 2-4 more weeks for the entire plant to turn red. The timing can vary depending on the size of the plant and other environmental factors.

Complete Darkness is Key

The most important thing is ensuring the plant receives 14 hours of complete, uninterrupted darkness every night Even a small amount of light leakage, like from a streetlight or nightlight, can disrupt the process and keep the leaves from turning red

During the day, the plant should receive as much bright, natural light as possible Strong light is needed to fuel the development of the red pigments Place the plant in a sunny south or west-facing window if growing it indoors.

Options for Providing Darkness

There are a few different options for how to give your poinsettia 14 hours of darkness each night:

• Place the plant in a spare closet or room with no windows. Be sure to block any light coming in from under the door.

• Cover the plant with a large cardboard box or opaque trash bag overnight. Weigh down the sides to prevent light leaks.

• Build a simple wooden box lined with black fabric or paint that fits over the plant.

• Move the plant to a location where it will naturally receive 14 hours of darkness, like a basement or enclosed porch.

Other Care Tips

In addition to the light manipulation, provide all the other care poinsettias need to thrive:

• Water whenever the soil feels slightly dry. Don’t let the plant wilt heavily.

• Apply a balanced liquid fertilizer every 2-3 weeks during active growth.

• Keep temperatures between 60-70°F (16-21°C) for best results.

• Increase humidity around the plant by placing the pot on a tray of pebbles and water.

• Remove any dried or damaged leaves and stems to encourage new growth.

Stopping the Dark Treatment

Once the bracts have turned fully red, you can stop the darkness treatment. Move the plant back into normal light conditions. The red color may fade gradually after a month or two, but you can enjoy the show through the holiday season.

With a little extra effort, you can force your poinsettias to turn red year after year. Just be sure to start early and provide complete darkness each night into early winter. Then you’ll be rewarded with a splash of festive color just in time for the holidays.