Poinsettias are a popular flower, especially during the holidays. Earlier this month, North Carolina State University hosted its annual poinsettia trials, co-sponsored by the N.C. Commercial Flower Growers Association. Each year, multiple private industry breeders come together to see who can grow the best flower, showcasing both old and new varieties. But how are these flowers grown, you might ask? I spoke with Dr. Brian Whipker, professor and commercial floriculture extension specialist at N.C. State University, for insight on the process.
“Mother plants are grown in Central America,” Dr. Whipker said, “root cuttings get shipped out to breeders like us and those get potted.” Root cuttings vary based on many factors, but the cuttings used in the 2019 poinsettia trials were potted on week 32, or Aug. 6, giving them a three-week growing process to the root system. Poinsettias are a form of “pinch plant”, meaning that the main stem is removed during the pruning process, forcing the plant to grow into two new stems. Pinching is done to give the plant it’s beautifully full form.
Poinsettias are also extremely light sensitive, lending them to change a variety of colors depending on the length of time the plants are left in the dark. According to Whipker, “Sep. 21 is the date that nights get long enough to begin altering plant coloration.” All the poinsettias grown and shown in the trials are 8-9-week varieties. Given this time frame, they acquire lots of pollen and show their full color.
The middle part of a poinsettia is the flower and the leaves are modified bracts. “Contrary to popular belief, poinsettias are not poisonous,” Dr. Whipker said, “It is just like any other plant. If you eat too much you will get sick, but they are not inherently poisonous to humans or animals.” A majority of poinsettia sales each year are the red variety popular for the holidays, but the white and pink varieties come in at a close second and third.
So, where did the idea of a poinsettia trial come from and what is the purpose? According to Whipker, around 25 years ago a national trial program for poinsettias was desired on a university level and only three universities consented to hosting, Florida, Perdue and N.C. State. Over the years, both Florida and Perdue have dropped out, leaving N.C. State as the only one currently hosting a paid trial. Breeders enter their own flowers, either putting a name or a number on each one. The trial varieties will go through a two-year evaluation process for coloring and a two-year send out process, making them four years old by the time they are named an official poinsettia variety.
North Carolina ranks second nationally in poinsettia production. In 2018, our state produced around 4 million potted poinsettias, bringing in over $14 million in production. The plants are grown indoors, in greenhouses to ensure the temperature is ideal for the plant. Avoid temperatures below 55 degrees and above 75 degrees to keep your poinsettia looking fresh this holiday season.
The varieties showcased in the 2019 poinsettia trials come from eight different breeders. Crowd favorites have been the “Beekenkamp Pon 127”, which is a red oak leaf poinsettia, and the “Beekenkamp Pon 112”, which is a white leaf poinsettia. After the poinsettia trial, the flowers are used by N.C. State grad students, local businesses and horticulture professionals around the area.