Get It Growing for 11/29/24

It’s official: The festive season is upon us. Thanksgiving has come and gone, and now it’s time to bring out the holiday decorations — if you haven’t already.

One item that adorns many of our homes this time of year is the poinsettia. Holidays are a great time to reflect on history and traditions, so before we talk about tips for selecting and caring for poinsettias, let’s learn a bit about this plant’s backstory.

The poinsettia is named for Joel Roberts Poinsett, who from 1825 to 1829 served as the United States’ first ambassador to Mexico, which had won its independence from the Spanish Empire just a few years prior. It was during Poinsett’s diplomatic travels in southern Mexico that he saw poinsettias — known by Aztec locals as cuetlaxóchitl — growing near the mining town of Taxco de Alarcón. An amateur botanist, Poinsett brought samples back to his home in South Carolina and shared the plants with his friends.

While other scientists had already discovered and described the species (Euphorbia pulcherrima), Poinsett helped popularize it. Americans were mesmerized by the crimson-colored plants, which early sellers hawked as cut flowers that they called Mexican flame flower or painted leaf. The name poinsettia caught on later. In the plant’s native growing range of Mexico and Central America, it goes by many names, including flor de Nochebuena (Christmas Eve flower).

Poinsettias have had a role in Christmas festivities since at least the 1600s, when Franciscan monks in Mexico began using them in nativity processions. Stateside, poinsettias took off in popularity in the 20th century largely by the efforts of California horticulturist Paul Ecke, who figured out how to grow them indoors in containers. This made the plants, with their merry red-and-green hues, more accessible to customers — and cemented their place as a holiday staple.

Most of us have a certain image in mind when we think of a poinsettia: a potted, 1- or 2-foot-tall plant with red flowers that we buy for holiday decorating and throw away a few weeks later. In their native environment, however, poinsettias live year-round as shrubs that can grow several feet high.

Thanks to research, there are dozens of varieties available nowadays in many colors besides the original red. And — get this — the colorful parts of a poinsettia plant aren’t actually flowers. Those are called bracts, or modified leaves, which change color with the shorter days and longer nights of fall and winter. The flowers, or cyathia, are the tiny green and yellow structures at the center of the bracts.

When you go shopping for poinsettias, select plants with small, closed cyathia, little to no yellow pollen and no sap. This will give you the best chance of having plants that will stay attractive for their maximum of four to six weeks. Plants with cyathia that have a lot of pollen and sap won’t last as long.

Also look for plants with several large bracts that cover the lower green leaves. Check underneath the foliage for insects such as white flies and avoid purchasing plants with yellow or drooping leaves.

At the garden center, you’ll likely encounter a broad array of colors — including the traditional red as well as white, several shades of pink, gold, orange and even marbled selections. You’re sure to find something to fit with any holiday design scheme.

If you want to make an even bigger statement, try a poinsettia tree, which is simply a poinsettia grown in a tree-like form with a single trunk. These are usually 3 to 4 feet tall.

Now, on to the subject of what to do with your poinsettias after you get home. You can put them outside in a front porch display, but keep in mind that poinsettias are tropical. They don’t like cold temperatures, nor will they be happy in direct sunlight. We recommend keeping your poinsettias indoors in areas with bright, indirect light. A sunny window is perfect. The proper amount of light is key to keeping good bract color and preventing leaf drop.

Try to keep poinsettias away from locations prone to sudden temperatures changes. In other words, don’t sit them next to a heating vent or an often-used door.

Water when the surface of the potting mix is dry to the touch, watering at the base of the plant rather than from overhead.

Poinsettias are somewhat brittle, so handle them with care. If you break off part of a plant, it will release a milky sap. Keep poinsettias away from children and pets. Contrary to popular belief, they are not poisonous. But they can cause nausea and other unpleasant symptoms if plant parts are ingested, and the sap can irritate the skin.

And yes, after the holiday season is over, you can try to plant your poinsettias outdoors. But keeping them protected from frost and getting them to develop colorful bracts outside of a controlled greenhouse environment is a struggle. It’s best to toss these plants once they’ve faded and embrace them as a once-a-year treat.

LSU AgCenter horticulturist Jason Stagg talks about how to choose poinsettias.

Many colors of poinsettias are available. Photo by Randy LaBauve/LSU AgCenter

Try to buy poinsettias with closed flowers that don’t have much pollen or sap. Photo by Randy LaBauve/LSU AgCenter

When choosing poinsettias to buy, inspect the undersides of leaves for insects, and ensure there are no yellow or drooping leaves. Photo by Randy LaBauve/LSU AgCenter

Larger poinsettia trees make a big statement. Photo by Randy LaBauve/LSU AgCenter

Some poinsettia varieties have bracts that are speckled or marbled with more than one color. Photo by Randy LaBauve/LSU AgCenter