The poinsettia, Euphorbia pulcherrima, is recognized globally as a symbol of the holiday season due to its vibrant, colorful leaves, known as bracts. While often treated as a temporary holiday decoration, this perennial tropical shrub native to Mexico can thrive as a houseplant year-round. Encouraging it to re-color requires understanding its distinct seasonal care needs, transitioning it from a blooming display piece to an actively growing foliage plant.
Essential Care During Active Bloom
A newly acquired poinsettia needs specific conditions to maintain its colorful bracts throughout the holiday season. Place the plant in a location that receives bright, indirect sunlight for at least six hours daily, such as near a south, east, or west-facing window. Avoid direct, harsh winter sun, but ensure maximum light exposure to prevent lower leaves from yellowing and dropping.
Maintaining the correct temperature is important for the plant’s longevity. Poinsettias prefer a temperature range of 65–75°F (18–24°C) during the day and 60–65°F (15–18°C) at night. The plant is highly sensitive to cold air and must be kept away from drafts from windows, doors, or vents. Exposure to temperatures below 50°F will cause chilling injury and lead to immediate leaf drop.
Watering should only occur when the soil surface feels dry to the touch, which typically means watering thoroughly about once a week. When watering, remove any decorative foil and allow the water to drain completely from the bottom of the container. Never allow the plant to sit in standing water, as this quickly leads to root rot. Fertilization is not necessary during the active blooming period.
Pruning and Transitioning the Plant
Once the colorful bracts begin to fade or drop, usually around March or April, the plant transitions to the vegetative growth phase. This is the ideal time for hard pruning to reshape the plant and encourage new growth. Cut the stems back severely, leaving about 6 to 8 inches of growth above the soil line.
Cut just above a node (a small bump or scar where a leaf was previously attached), as this is where new growth will emerge. Wear gloves during this process because the poinsettia, a member of the Euphorbia family, produces a milky white sap, or latex, that can be a skin irritant. After pruning, reduce watering and keep the plant in a bright, warm location until new green shoots emerge.
The onset of new growth in the spring is also the time for repotting, especially if the plant has been in the same container for a year. Move the poinsettia into a container that is only slightly larger than the previous one, ensuring excellent drainage. Use a fresh, well-draining potting mix.
Summer Growth and Fertilization
With the arrival of warmer weather, the poinsettia enters its active growing season, requiring regular feeding. Once new shoots are several inches long, begin fertilizing with a balanced, water-soluble houseplant fertilizer. Apply this every two to four weeks throughout the spring and summer at half the recommended strength.
Move the plant outdoors once all danger of frost has passed and nighttime temperatures are consistently above 55°F (13°C), typically in late May or early June. Place the container in partial shade, protecting it from intense, direct midday sun that can scorch the leaves. When outdoors, the plant will need more frequent watering, but ensure the soil drains well.
To encourage a full, bushy shape, a process called “pinching” should be performed on the new growth. Pinching involves removing the top inch of the new stems, leaving about four to five leaves per stem. This technique encourages the plant to branch out, and it should be repeated monthly until early September to maximize the number of stems that will bear colored bracts. Monitor the foliage for common pests like whiteflies and spider mites.
Inducing Color for the Next Season
The most precise step in year-round care is the photoperiod manipulation required to induce colored bracts. Poinsettias are “short-day” plants, meaning they require a prolonged, uninterrupted period of darkness each day to trigger the chemical process that changes the bracts’ color. This induction process must begin around late September or early October and continue for eight to ten weeks to be ready by mid-December.
The daily routine involves providing the plant with 14 hours of absolute, uninterrupted darkness followed by 10 hours of bright light. The darkness must be complete; place the plant in a closet, cover it with a light-proof box, or move it to a room where no light, even from a streetlamp, can reach it. Even a brief flash of light during the dark period will interrupt the process and reset the plant’s internal clock, delaying the color change.
During this induction period, maintain the night temperature in a cooler range, approximately 60–65°F (15–18°C). Once the bracts show significant color change, typically by late November or early December, the strict darkness regime can be stopped. The poinsettia can then be returned to bright, indirect light conditions to display its full color for the holiday season.