It’s hard not to feel a sense of celebration this time of year, with all the lights, the music, the gatherings and the decorations going up in churches, homes, businesses and the public square. But it’s when the poinsettias suddenly appear that I know Christmas is almost here. Retailers can keep pushing back holiday sales and promotions, but poinsettias have a very limited, almost fleeting shelf life, so you can’t jump the gun with them. For that reason, I feel they are the true harbingers of the season.
About 25 years ago, I worked as a horticulturist for a company that maintained foliage plants in office and commercial spaces, and the occasional home. During the holidays, our workload practically doubled as we delivered, staged and maintained hundreds of poinsettias all over the Denver-metro area. The colors, ranging from bright red to speckled pink to creamy white were magical, and we were greeted with exclamations of delight and joy when we arrived.
Inevitably, joy turned to concern in some locations when we returned days later to find bare spots where leaves and bracts had wilted or fallen, and holes where the tiny flowers, called cathia, had expired in some locations.
Nothing looks worse than a stressed-out poinsettia, and since they often command premium prices, knowing how to care for one can save you from holiday disappointment.
Kansas State University Extension Horticulturist Ward Upham knows a thing or two about poinsettias. It’s been several years since I’ve taken care of a poinsettia so turning to him for advice for this article made sense. Finding a well-lit, draft-free location for your point is a good first step towards ensuring it lasts throughout the holiday season.
“Try to place it in as bright as light as possible,” he said. “They are used to greenhouse conditions and lower light levels in the home may lead to leaf drop.”
Like with most other plants, poinsettia leaves act as little solar energy collectors. If there’s not enough sunlight available, plants will shed what it has no use for in a bid to conserve energy.
Temperature is a factor. Poinsettias thrive when daytime temperatures range from 65 to 75 degrees Fahrenheit. At night, they don’t mind a slight drop from 60 to 65 degrees. Lower temperatures damages the roots, and you could end up with rot.
Proper watering is important too. If you’ve ensured your poinsettia has enough light and is warm enough, and it’s still dropping leaves or wilting, watering might be the contributing factor. The roots need to breathe, so keeping them too wet can lead to root rot, but if they dry out, they will wilt and the leaves will curl and drop off. It’s best when you bring your plant home that you give it a good drink, allowing water to drain out. Removing the grow pot from the container and watering in the kitchen sink is a good idea. Once it’s stopped draining, return the grow pot to whatever decorative pot or foil wrapping it might have come in.
Especially for the first few days, examine the potting soil daily by sticking your finger about one-half inch deep into the soil, Upham recommends. If it is dry to this depth, the plant needs water. Keep in mind that plants acclimate to their new environment over a few weeks, so at first, its water intake will be higher as it transitions from the greenhouse to your home. Never water unless you check the soil first.
Be sure to remove any dropped leaves, and be sure to wash your hands after handling poinsettias. They are part of the Euphorbia family, so the white sap present when leaves drop or stems are accidentally broken is a skin irritant, not only for humans, but for your pets too. It’s recommended to keep poinsettias away from where dogs, cats or kids frequent.
Poinsettias are susceptible to spider mite damage, especially since they require lots of light. That’s where you’ll find spider mites thrive inside your home, by the way. If your plant looks stressed, look closely on the underside or between leaves for fine webbing. If its there, you have mites. But don’t worry — treatment is easy.
“Turn the plants upside down and rinse in sink or tub with lukewarm water,” Upham said. Check again periodically, because you may need to do it more than once during the season.
If you’ve followed these simple steps, your poinsettia may keep going for many weeks after the holidays are over. Some people even keep them going year round. If you are so lucky, check out Upham’s tips for reblooming.
According to a KSU Extension fact sheet, poinsettias were introduced into the United States in 1825 by Joel Robert Poinsett. He served as the first United States ambassador to Mexico, appointed by President Andrew Jackson in the 1820s. He discovered the wild plants growing on hillsides near Taxco, located about 106 miles southwest of Mexico City. He sent plants to his home greenhouses in Greenville, South Carolina, and began giving plants to botanical gardens and horticultural friends, including a nurseryman in Philadelphia who started the first commercial propagation and sales from some of these plants.
The Ecke family, California, is credited with developing the modern poinsettia industry. Breeding research started during the mid-1950s led to many of the improved cultivars we enjoy today.
Kansas State University Extension Horticulturist Ward Upham provided the following information on reblooming poinesttias:
If you have saved last year’s poinsettia and want it to flower again this year, you must follow certain procedures. Poinsettias are known as “short-day” plants. Growers found out long ago that poinsettias can be brought into bloom if they are given short days and long nights.
Originally, it was thought that short-day plants needed a short duration of daylight in order to flower. Now we know that flower formation is actually triggered by long periods of uninterrupted darkness. For poinsettia, at least 12 hours of each 24 must be uninterrupted dark. Night temperature also has an effect and should be below 70 degrees F with 60 to 65 degrees F preferred.
During the day, place the plants in the sunniest location of the house. This high level of light is needed for the plants to have the energy required for good bract coloration. Day temperatures should range between 65 and 75 degrees F.
Providing uninterrupted darkness can be a problem for gardeners unless there is a room in which the lights are never turned on. If you don’t have such a room, place your poinsettia in a dark closet or cover it with a cardboard box each night for the required 12 hours. If using a cardboard box, tape all the seams with duct tape to cut off any light. Poinsettia takes anywhere between eight and 11 weeks to flower once the dark treatment has been started. Normally, people start the dark treatment early- to mid-September. The first six weeks are critical. For every night you miss during the first six weeks, add two days to the bloom time.
After the six-week dark treatment, the buds have set and the dark treatment is no longer needed.