Poinsettia

Family:Euphorbiaceae (Spurge Family)
Genus: Euphorbia
Species: pulcherrima

I’m going to try to raise the bar a bit this month, the last of the year, and so I’ve chosen a topic that I hope will move us quickly away from the images in last month’s newsletter: rosemary growing in coffins and spiders lurking in our beds (thanks, Todd, for that swell image. Took my mind right off rosemary. I’m searching for one of those chin-strap contraptions that will keep my mouth securely closed while I sleep!). And if you, dear readers, want anything more to worry about in the spider department, snag Todd and let him tell you the latest about eating bugs by happenstance as well as by choice. Spiders and cream cheese on crackers, indeed….

In one of my Master Gardener classes, Craig MacConnell suggested we think of houseplants as “long-term perishables,” and that description has always worked for me. I don’t write about them too often, since the plants that live outside are always clamoring for attention, but indoor plant care is part of our mission and we do get questions about them in clinics. This time of year, we’re likely to get calls about the care of poinsettias during the holidays, and whether or not they can be successfully kept over from one year to the next. After all, more than 65 million poinsettias will be sold in the U.S. during this holiday season, better than 90 percent of them from one grower in Encinitas, California.

There are more than 1,600 species in the genus Euphorbia, native worldwide. They vary wildly in their cultural requirements and growth habits. E. pulcherrima is actually a large shrub that is native to southern Mexico and Guatemala. Legend has it that these striking plants were cultivated by the Aztecs for aesthetic, ceremonial, and even medicinal purposes. Even then, there was a taste for exotic plants: E. pulcherrima was difficult to grow in the Mexican capital because of the climate, and therefore it was highly prized. After the Spanish arrived, many new legends grew up about the plant, all of them associated with Christian celebrations. In 1825, the first U.S. ambassador to Mexico, Joel Poinsett, was smitten by the plant’s brilliant color. He sent some back to his South Carolina greenhouses where they were cultivated and shared with friends. Soon they were in the hands of Robert Buist, the first nurseryman to sell the plant as Euphorbia pulcherrima. For the last century, the cultivation of poinsettias and their distribution during the holidays has been dominated by the Ecke family, whose poinsettia ranch is near San Diego. Today, poinsettias are used to a small extent as landscape plants in the south, but their primary use is decorative, between mid-November and January each year.

While all members of the spurge family have a milky sap (latex) that can cause a rash in many people, poinsettias are not poisonous. An urban legend that all parts of the plant were lethal has persisted since 1919, when it was rumored that the death of a small child was caused by eating the leaves. In 1975, the United States Consumer Product Safety Commission rejected a petition to require warning labels on poinsettias. That doesn’t mean that you should add them to your salad; but if you get a call that a cat has nibbled some part of the plant, you can assure the client that their little Boots will escape with a sore tongue, at worst.

The glorious color of poinsettias—red, cream, pink, or a combination—is found in their bracts—modified leaves—rather than in their flowers, which are quite insignificant. Thanks to applications of growth inhibitors, they range in size from tiny to knee-high. Their owners’ primary purpose is to keep them looking lush for up to four weeks, and that can be accomplished by giving them as much light as possible and keeping the growing medium evenly moist. Don’t let them stand in water, and try not to put them right next to the fireplace—although it is a grand place for them, isn’t it? They don’t need to be fed, since they’ve been given all they need by the time they arrive in the stores. Expect some leaf drop a couple of days after you bring them home: they’re very sensitive to changes in their surroundings. Essentially, they begin to decline when they leave the growers’ controlled environment, so just do the best you can to keep them looking good for as long as possible.

Holiday poinsettias are really short-term perishables, tropical plants that are sufficiently manipulated to last only through the holidays. You might think of them as floral decorations rather than houseplants. It is futile to try and keep them going much past New Year’s, so be strong…chop them up…and put them in your compost. That way they’ll do their best to contribute to the health of your plants that are intended to last more than a few weeks. Enjoy them while you can, for they do add a colorful note to holiday festivities. And, by the way, I send my best holiday wishes to each of you. May your days be merry and bright…and may your garden grow strong in 2001.