The perennial poinsettia

By Deborah J. Benoit

Editor’s note: Deborah Benoit is a University of Vermont extension master gardener. 

During the holidays, poinsettias (Euphorbia pulcherrima) show off in shades of red, pink, and cream. They’ve been hybridized to decorate our homes during a season when the garden outdoors is fast asleep. Most people treat them as a holiday plant to be enjoyed for a limited time then disposed of, but that doesn’t have to be.

Poinsettias are a perennial. That means that they can live long after the holiday season is over. In their native habitat of Mexico and Central America, they are large shrubs standing up to 10-15 feet tall, reblooming year after year. Because poinsettias are hardy in U.S. Department of Agriculture plant hardiness zones 9-11, they will not survive outdoors year round in the Northeast. However, they will make a fine houseplant.

Poinsettias prefer bright light, temperatures between 65-80 degrees Fahrenheit, free of cold or hot drafts, and moist, but not wet soil. The first thing to do when you bring home a poinsettia is to remove the foil covering on the pot.

Place the pot in either a saucer or decorative cachepot where you can see and remove any standing water. Thoroughly water when the soil feels dry.

Allow any excess water to drain away, then empty it from the saucer or cachepot. Never let it sit in water. Soggy soil will cause the roots to rot and leaves to curl and fall off.

Place the poinsettia near a window, but don’t let the leaves touch the glass. Avoid cold and hot drafts. With a little care, your poinsettia will be happy and healthy through the holidays and beyond. And while the green foliage is lovely on its own, with the right conditions, your poinsettia can bloom again.

In January, you may notice some leaf drop, and the remaining colored leaves (called bracts) will turn green. At this point, you have a choice. You can either treat the poinsettia as you do your other houseplants and let nature take its course, or you can intervene to force it to bloom during the next holiday season.

In nature, as daylight hours grow shorter, the poinsettia’s bloom cycle begins. While the colored bracts of a poinsettia appear to be the plant’s flower, they serve a special purpose, to attract pollinators to their center.

Popular recommendations to force a poinsettia to rebloom include cutting back on watering and pruning the poinsettia to 6-8 inches high when leaves begin to fall after the holidays and keeping it in a cool location (around 60 degrees Fahrenheit). When new growth appears, return to watering as usual and fertilize according to package instructions.

As fall approaches, the tricky part begins. Make sure the plant receives at least 14 hours of total darkness by either covering it or moving it to a closet during those hours. When the bracts begin turning color, return the plant to a window where it can receive bright light.

A far easier method is to treat the poinsettia like any other houseplant. Place it in a south, east or west window. Care for it by watering as needed throughout the year.

Like any other flowering houseplant, your poinsettia will benefit from fertilizer. Apply it according to directions.

As the days begin to shorten, the bracts will begin to change color. The change from green to red (or whatever the color for that particular plant) will progress without any special treatment. Buds will form at the center of the bracts, and the poinsettia will flower.

In short, this year’s poinsettia can take its place among your other houseplants, and with a little TLC, next holiday season, it can celebrate with you again.