Yes, the poinsettia, Euphorbia pulcherrima, can turn red again after the season ends. This popular plant is native to Mexico and Central America and is celebrated for its festive appearance. The bright red structures are not true flower petals but specialized leaves called bracts, which surround the small, yellow flowers at the center. With specific year-round care and environmental manipulation, you can successfully coax these bracts back into their brilliant color for the following holiday season.
Understanding the Poinsettia’s Color Cycle
The color change in poinsettias is photoperiodism, the plant’s response to the length of day and night. Poinsettias are short-day plants, meaning they require long, uninterrupted darkness to trigger flowering and pigment production in the bracts. The colorful bracts serve a function in nature, attracting pollinators to the tiny flowers housed within them.
After the holidays, the bracts often begin to lose their color and fade back to green, which is normal for the plant. This fading occurs due to natural aging and continuous exposure to longer daylight hours and artificial light found in most homes. The plant needs to sense the shift to shorter days and longer nights to restart the color cycle.
Essential Care During the Growing Season
A successful color change in winter depends on maintaining a healthy plant throughout the spring and summer months. Once the bracts have faded or dropped, cut back the stems to about four to six inches in height. This pruning encourages new, bushy growth, which is necessary for a well-shaped plant later in the year.
After pruning, repot the poinsettia into a slightly larger container using fresh potting soil to support root development. Once new green growth appears, begin fertilizing every two weeks with a complete houseplant fertilizer. During this active growth phase, keep the plant in a location that receives bright, indirect sunlight for at least six hours daily.
When the danger of frost has passed and nighttime temperatures are consistently above 50°F, move the plant outdoors for the summer. Place the poinsettia in a spot with part sun, making sure to water it frequently, as outdoor conditions can cause the soil to dry out faster. To ensure a full, round shape, pinch back the stems by about an inch in mid-summer, but stop all pruning by early September.
Inducing Color Change Through Darkness
The process for re-coloring the bracts must begin around late September or early October, eight to ten weeks before you want the color display. This forcing period requires the plant to receive 12 to 14 hours of complete, uninterrupted darkness every night. The darkness must be absolute, as even a small amount of light from a streetlamp, a television, or a crack under a door can disrupt the process and prevent color formation.
During the day, the plant must receive six to eight hours of bright daylight. This means you must manually move the plant or cover it with an opaque box or bag every evening and uncover it every morning. This daily routine must be maintained for eight to ten weeks, or until the bracts have developed their color.
Temperature control is important during this phase, as optimal temperatures help accelerate the color change. During the day, temperatures should be maintained between 60°F and 70°F, with a slightly cooler range of 55°F to 60°F at night. Once the bracts have fully colored, usually by late November, the darkness treatment can stop, and the plant can be placed back in a sunny location.