Updated: Dec 13, 2019
December 12th is National Poinsettia Day, dedicated to the amateur botanist who brought the Poinsettia to our country in the early 1800’s. His name was Dr. Joel Roberts Poinsett, and we have been celebrating National Poinsettia Day every year since the mid-1800’s. Over 35 million Poinsettias are sold each year, greatly eclipsing any other potted perennial plant in annual sales. The closest competitor is the Easter Lily, at 26 million a year.
Did you know that, similar to Dogwood tree blooms, the parts that we call petals, typically bright red on a poinsettia, are not petals at all but are leaves called bracts? The Poinsettia flower is actually a much smaller cluster of flowers in the center of the bracts called cyathia.
Poinsettias come in a range of colors from red, the most popular, to white, pink, apricot, yellow, and even speckled varieties. If you see a blue Poinsettia though, mother nature doesn’t get the credit; the blue color has been applied with dye. I fell in love with a mottled white and red specimen at my local nursery this year. These beautiful plants are members of the Euphorbia family (Euphorbia pulcherrima) and are often considered the quintessential winter holiday plant.
Poinsettias are native to Southern Mexico and Central America, and can grow to the size of a small tree, up to twelve feet, in their native habitat. Historically, this plant’s leaves were used for dying clothing, and the sap was thought to lower fevers.
Poinsettias used to only bloom for a few days in our climate. In the 1960’s, horticulturists were finally able to develop Poinsettias that would bloom for the holiday season in December. One of the most common questions people ask about Poinsettias is now to extend their blooms longer, even into the following year.
One of the most important things to remember about maintaining Poinsettias is that they are extremely sensitive to light and temperature. For example, a Poinsettia may begin to drop its leaves and go dormant if it feels a draft or a prolonged drop in temperature on the ride home in the car from the store from which it was purchased! So my top piece of advice is to wrap it with a cloth or blanket on the way home and then keep it in a window with bright, but indirect light in a room between 65 to 75 degrees Fahrenheit without drafts.
Want to try growing Poinsettia throughout the year and get the plant to bloom again the following year? This is a tall order. In order to have the best chance of success the Poinsettia will need to be kept in the conditions listed above, without drafts or drops in temperature until around October 1st of the next year. Then an eight-week long regimen of complete darkness for 12-15 hours each night is required, then back to indirect sunlight during the day. Experts warn the best way to achieve this in our climate is to put a box over the plant at night with no light leaking in around it. After the eight week period you should start to see blooms forming just in time for the holidays. For those of us who don't want to deal with this task, buying a new Poinsettia each year is the way to go.
Are Poinsettias poisonous? According to scientists, a child would have to eat over 500 Poinsettia leaves in order to risk poisoning. I don’t know about you, but I don’t know any child who would eat two Poinsettia leaves, let alone 500. The milky sap, which can be a skin irritant to humans, can pose a mild threat to our furry friends. The sap contains chemicals called diterpenoid euphorbol esters and saponin-like detergents. If enough is ingested, it can cause drooling, vomiting, and diarrhea in cats and dogs. Although rare for pets to ingest enough sap for severe reactions, there is no antidote for Poinsettia poisoning, so error on the side of caution if you know your pet likes to chew plants and put them on a high mantel or shelf or enjoy the plant at a friend’s house instead. Happy Gardening and Happy National Poinsettia Day!