Poinsettias are a classic holiday plant, with their brilliant red, pink, or white leaves brightening up homes during the winter season. But once Christmas passes, the colorful bracts fade and fall off, leaving you with a regular green houseplant. If you want to revive that festive color next holiday season, you can! With some simple steps, you can get your poinsettia to turn red again
Why Poinsettias Change Color
Poinsettias are native to Mexico and Central America where they change color during the winter in response to shorter daylight hours. As the nights get longer, poinsettias undergo a physiological shift that induces them to produce colorful bracts.
The red color comes from modified leaves called bracts that surround the tiny yellow flowers Forcing your poinsettia to turn red again just requires mimicking those short daylength conditions
When to Start the Process
To get your poinsettia to change color, you need to modify its exposure to light starting in early October. The plant needs a minimum of 14 hours of complete darkness each night for about 8-10 weeks.
Ideally, begin the treatment at least 8 weeks before you want the plant to be fully red. It usually takes 4-6 weeks before you start noticing the leaves changing from green to red Allow another 2-4 weeks for the entire plant to develop full color Timing varies depending on the size of the plant and growing conditions.
Complete Darkness is Essential
The most critical factor is giving the plant 14 hours of uninterrupted darkness every night. Even a small amount of light leakage from a streetlight or nightlight is enough to disrupt the process and prevent the leaves from turning red.
During the day, the poinsettia needs as much bright, natural light as possible to fuel the production of red pigments. Place it in a sunny south or west-facing window when growing indoors.
Options for Providing Complete Darkness
There are several ways to ensure your poinsettia gets its 14 hours of darkness each night:
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Put the plant in a spare closet or windowless room. Block any light coming in under the door.
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Cover the poinsettia with a large cardboard box or opaque trash bag overnight. Weigh down the sides to prevent light leaks.
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Build a simple wooden box lined with black fabric or paint to fit over the plant like a tent.
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Move the plant to a naturally dark location like a basement or enclosed porch.
Additional Care Tips
Along with manipulating light exposure, provide all the other care poinsettias need:
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Water whenever the soil feels slightly dry. Don’t let the plant wilt heavily.
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Fertilize every 2-3 weeks with a balanced liquid fertilizer during active growth.
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Keep temperatures between 60-70°F (16-21°C) for best results.
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Increase humidity by placing the pot on a tray of pebbles and water.
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Remove dried leaves and stems to encourage new growth.
Stopping the Darkness Treatment
Once the bracts have turned fully red, you can stop the darkness treatment and return the plant to normal light conditions. The colorful leaves may fade gradually after a month or two, but you’ll get to enjoy the full show through the holiday season.
With a little extra effort starting in fall, you can force your poinsettias to turn red year after year. Just be diligent about providing 14 hours of complete darkness each night into early winter. Then you’ll be rewarded with a pop of festive color just in time for the holidays!
The Red Parts Aren’t Actually Flowers
The red portions of poinsettias aren’t technically the flowers. They’re modified leaves called bracts. The flowers are the tiny yellow clusters found in the center of the bracts. The bracts are simply larger and more colorful, helping attract pollinators to the real flowers.
Frequently Asked Questions
How do you force a poinsettia to turn red?
Poinsettias need 14 hours of uninterrupted darkness each night for about 8-10 weeks, starting in early October. During the day, give them bright light and normal care. The complete darkness triggers the development of red bracts.
How can I restore the red color on my poinsettia?
In fall, place the poinsettia in a warm spot where it gets 14-15 hours of complete darkness every day. This mimics the short daylengths that induce flowering. Once the bracts turn red, you can stop the darkness treatment.
Do poinsettias like coffee grounds?
Yes, used coffee grounds are great for poinsettias. The extra acidity from coffee grounds creates ideal growing conditions for poinsettias that prefer slightly acidic soil. Simply mix some grounds into the potting soil.
How do you revive a dying poinsettia?
Starting October 1st, give your poinsettia 14 hours of darkness each night by moving it to a closet or covering with a box. Keep in bright, indirect light during the daytime. This extended darkness will initiate reblooming by Christmas.
Getting your poinsettia to turn red again takes a little effort, but it’s easy enough with the right light conditions. Follow these tips starting in fall, and you’ll have a festively colored plant to enjoy each holiday season.
How to rebloom your poinsettia
Updated from an original article written by Gretchen Voyle.
Reblooming your poinsettia can be a fun and rewarding activity.
Euphorbia pulcherrima. Photo by Scott Bauer, USDA Agricultural Research Service, Bugwood.org.
Having a poinsettia plant during the winter is a tradition for many people. You may ask yourself if its possible to get the plant to bloom again next year. It is! Poinsettias require specific light conditions to allow the plant to make flowers again. This requires some management to get it to bloom for the holidays.
Poinsettias have been considered a holiday plant in the United States since the 1820s. Its botanical name is Euphorbia pulocherrima, and it is a member of the Euphorbia family. Like many Euphorbias, it has a white milky sap that can cause skin irritation.
The common name “poinsettia” is derived from the name of the first U.S. Ambassador to Mexico, Joel Roberts Poinsett. Poinsett brought cuttings to the United States in the 1820s and introduced them to plant enthusiasts. Poinsettias are native to Mexico and Central America. In its native range, the plant is a perennial shrub or small tree which can grow up to 13 feet tall. These wild plants have similar but less exaggerated features compared to the cultivated varieties that can be purchased in stores.
The parts of the plant that we often call flowers are technically “bracts” surrounding the tiny round flowers. Bract is a scientific term for a modified leaf. These bracts differ in color from the other leaves on a poinsettia. Various bract colors in todays market include red, pink, white and green. These colors can be in solid, speckled or even marbled patterns. In addition, some are dyed artificial colors or covered in glitter before being sold. These are often turquoise, blue, purple or vivid green. Eventually, these plants will lose their colored coatings as they grow new bracts.
Proper care is crucial for the longevity of your poinsettias blooms. If the pot your poinsettia is in has a decorative foil or plastic covering, its essential to remove it to prevent water from accumulating and causing root rot. Poinsettias thrive when placed near a west or south window, receiving some sun during the day. Remember to water only when the surface of the potting soil becomes dry.
Your poinsettia should be moved outdoors during summer so that it can receive adequate light. You can move your plant outdoors when temperatures are consistently above 50 degrees Fahrenheit. This is usually around the end of May. Find a location outdoors where the plant will receive strong morning sunlight. The plant will stretch in low-light environments, resulting in weak branches and a top-heavy plant. If your plant has not received consistent light indoors, you may need to slowly transition it into the sun so it does not burn. This can be done by placing it in partial sun for short periods and increasing the amount of light over one to two weeks. Remember, this is not a cold hardy plant. Temperatures below 50 F may damage the plant, and freezing temperatures will likely kill it.
After moving the plant outdoors, cut the stems back to about 5 to 6 inches and make sure some leaves remain. As new shoots grow, the tips of the stems can be pinched periodically to make the plant bushier. This involves clipping the very tip of the stem. Using a balanced fertilizer, water and fertilize the poinsettia to stimulate growth. Fertilizer can be applied every three to four weeks following the label recommendation for indoor plants.
Repot the plant in the late summer with fresh potting media. You may need a bigger container. This needs to be done before nighttime temperatures begin to drop. When night temperatures reach 50 F, bring your plant back indoors. Find a location where the poinsettia will get 14 hours of continuous, uninterrupted darkness and 10 hours of bright light. Some varieties may need as little as 10 hours of darkness, but 14 hours ensures rapid bloom initiation for all varieties. Timed lights can be helpful for this process. Some people will move the plant into a dark room or closet. Others will put it under a cardboard box for 14 hours. If you turn on the light, even for a brief time, it can affect the production of flower buds. Small amounts of light, such as a streetlight, car headlights, or the light from a TV can interfere with the production of blooms. Continue this cycle for up to two months until you begin to see colored bracts appear. If your poinsettia was colorized or dyed, the flower color will differ from when it was purchased. While it would be very cool, purple with glitter does not exist in nature.
It can take significant work to get another year out of a poinsettia. You may decide that this process isnt for you, and thats OK. You may choose to buy a new plant instead of reblooming your current one. Still, if youre feeling adventurous, reblooming can be a fun activity!