Perpetual Poinsettias

Cherise Skeba, Dakota County Master Gardener

Christmas is over and leaves are starting to fall off your once-flourishing poinsettia plants. Most people throw away Poinsettias and buy new plants each winter. Instead, consider saving a plant’s life and the Poinsettia will reward you with beauty throughout the year. If you enjoy Poinsettia’s and are willing to care and feed this lovely plant throughout the year, read this article for some great information about saving your Poinsettia for another beautiful display during next year’s holidays.

Poinsettias’ Story

The Euphorbia Pulcherrima plants are native to Mexico and Central America. The plants became known by their more common name, Poinsettia, in honor of Joel Roberts Poinsett, the first U.S. Ambassador to Mexico, who brought the plants to the U.S. in the 1820s and cultivated the plants in his South Carolina greenhouse. However, Poinsettias were not a popular plant in the U.S. until after the Ecke family founded their Encinitas, California Ecke Ranch in the 1920s and developed, by the 1950s, a way to mass-produce a compact Poinsettia varietal that could be potted as an indoor plant. In the 1960s, the Ecke family promoted Poinsettias as a Christmas plant by sending free plants to television studios who then featured the plants on shows such as Johnny Carson’s Tonight Show and Bob Hope’s Christmas Special.

Today, about 35 million Poinsettia plants are sold each year in the U.S. making Poinsettias the best-selling potted plant in the U.S. Amazingly, 70% of all commercially grown Poinsettias in the U.S. are still grown at the Ecke Ranch.

Anatomy of Poinsettias

Poinsettias’ flowers are found in the small yellow-green clusters known as cyathium, a unique feature of the Euphorbia genus. Cyathium is an aggregate of several very small male flowers and a single female flower wrapped in the involucre.

scientific diagram of Euphorbia Pulcherrima]

The larger colorful parts of the Poinsettias are modified leaves known as bracts. Leaves are bract when attached to the axil of a flower (i.e. the node that connects the flower to a plant stem) versus non-bract leaves that are attached directly to plant stems. Poinsettias’ bracts are considered “modified” because the bracts change color in the winter due to a process called photoperiodism. Shorter days and cooler nights trigger the plant to stop producing green chlorophyll which promotes visibility of the leaves’ red pigments called anthocyanins. The colorful bracts attract pollinators, but bracts will drop off the plant after the flowers are pollinated.

Winter To Spring Enjoyment

In colder climates, indoor potted Poinsettias can remain colorful for several months with the right environment and a little bit of attention. Poinsettias will thrive best in warmer air temperatures, ideally between 65 degrees and 70 degrees, and in spots where the temperature remains stable. Avoid placing Poinsettias near cold windows, air vents, fireplaces or fans. Poinsettias like 4-6 hours of bright light during a day but longer hours of light or too much direct sunlight may cause the bracts to fade. Poinsettias need moist soil. If the soil feels dry, put the Poinsettia in a sink and water until it drains from the bottom of the pot. Do not allow Poinsettia roots to sit in water (may need to remove decorative wrapping). Also, do not allow Poinsettias to become so dry that the leaves wilt.

Start fertilizing monthly when new growth appears in January or February. Use fertilizer at about half strength. Sprinkle additional potting soil on the surface if the Poinsettias’ roots are peeking up from the soil. Trim off wilted and brown leaves as they die. Remove any dead leaves from the soil.

Following the above simple maintenance steps should keep Poinsettias beautiful and healthy from November through February, and possibly longer.

Christmas Renewal

Poinsettia plants that look healthy in March are good candidates to keep alive for enjoyment the following Christmas. Poinsettias will drop their colorful bracts and flowers during March/April which signals the plants to grow. A healthy plant will have plentiful green leaves and stems and ideally will have a few new shoots peeking out from stem joints. Poinsettias can then be periodically pruned and shaped to promote more branching and create a more compact, full plant. Continue to follow the steps specified above for spring maintenance.

At the end of May, Poinsettias should be cut back to about 5-10 inches and transplanted into larger pots. Poinsettias may remain year-round house plants or may be moved outdoors in June or July when the night temperatures remain above 50 degrees (preferably above 60 degrees). Poinsettias need 4-6 hours of direct sunlight in the summer to stimulate growth. In addition, increase the fertilizer to full strength during the summer months.

Bring outdoor Poinsettias indoors early in September to protect the plants from cooler night temperatures. The plants should remain in a brightly lit area for another 2-4 weeks, but fertilization should be reduced to about 25% of normal strength to slow growth.

To produce colorful bracts and flowers, Poinsettias need 16 hours per day of complete darkness and 6-8 hours per day of light starting late September through late November. Temperatures during the dark periods should ideally be in the low 60s. Poinsettias should continue to be watered and fertilized at a reduced rate during these weeks. When colorful bracts appear in late November, Poinsettias can be moved to a sunny room and enjoyed through the Christmas holidays!

Lessons From Real-Life

I brought home six smaller Poinsettias last Christmas after volunteering at a banquet where the Poinsettias were used as table centerpieces. With regular watering, the Poinsettias remained compact and colorful through the winter months. By early spring, I faced the annual decision about what to do with the Poinsettias. I heard from friends that you could grow Poinsettias year-round which led me to keep the three healthiest looking Poinsettias. The red bracts eventually fell off the Poinsettias and I was left with three attractive green house plants.

Someone gave me an article about caring for Poinsettias but I confess, I didn’t read the article until late October. Consequently, I put the Poinsettias in a dark place late October with a grow light that came on for only six hours per day. I used a grow tent that could be zippered closed to exclude light but I read that any dark place could work. I watered the plants once per week and ignored the Poinsettias between waterings. I pulled the Poinsettias out from hiding the second week in December and magically, red bracts had appeared!

I’ve heard anecdotes that maintaining beautiful Poinsettias is challenging and I admit that my Poinsettias do not look as bushy as store-bought Poinsettias. However, I learned that Poinsettias are resilient and appealing, even with minimal care. In the coming year, I plan to follow more of the recommended Poinsettia care steps to enhance the beauty of my Poinsettias. The key changes that I plant to make to produce healthier Poinsettias are:

Transplant the Poinsettias into larger pots in late spring.
Fertilize the Poinsettias every month during the summer and fall.
Regularly trim the Poinsettias to promote bushy plants.
Shorten the Poinsettias’ daylight starting the end of September.
Ensure that the Poinsettias never become too dry.

I encourage you all to treasure your Poinsettias and experiment with keeping you Poinsettias year-round. The Poinsettias will thank you with their vibrant beauty every Christmas!

References:

“Cuetlaxochitl: A Cultural History of the Poinsettia”, Swanson Nursery

http://www.swansonsnursery.com/blog/history-of-poinsettias#:~:text=The%20timing%20of%20the%20annual,transformation%20during%20the%20holiday%20season

“Growing and caring for poinsettia”, University of Minnesota

http://extension.umn.edu/houseplants/poinsettia

“About the genus Euphorbia”, Euphorbia Planetary Biodiversity Inventory project

http://euphorbiaceae.org/pages/about_euphorbia.html

“Guide to Selection and Care of Poinsettias”, Iowa State University

http://yardandgarden.extension.iastate.edu/how-to/guide-selection-and-care-poinsettias

“How Can I Keep My Poinsettia Alive Beyond the Holidays”, Utah State University

http://extension.usu.edu/news_sections/home_family_and_food/poinsettia-care

“Poinsettia: America's most popular flower”, University of Missouri