I've noticed over the last couple of weeks that a few early-season poinsettias are showing up on garden center shelves. And while we're celebrating Thanksgiving this week, the appearance of the poinsettia means we are in the full swing of the Christmas season.

Traditionally, the red poinsettia is the first choice of many holiday gardeners.

Gary Bachman

The color possibilities of poinsettias are truly remarkable. Colors range from red to white and even maroon for Bulldog fans, making it hard to choose which ones to bring home. There are bicolored, speckled and marbled poinsettias, and if that's not enough, some greenhouses are even changing colors by painting them and adding sparkles.

When shopping for poinsettias, be aware of the wide variety that is available. Take your time to select the very best.

Now I need to point out that the colorful “flowers” that we love so much are not flowers at all. They are actually modified leaves, called bracts. Poinsettias naturally change color in the short days of winter in their native Mexico, but to get the poinsettias ready for garden centers, greenhouses trick the plants by using shade cloth to block light. As we get closer to Christmas, more color will be showing, finally becoming a sea of radiant hues.

The appearance of poinsettias means we are in the full swing of the Christmas season. (Photo by MSU Extension/Gary Bachman)

While their leaves provide the real color, poinsettias do have true flowers: the yellow/green bead-like structures called cyathia. Your poinsettia will last longer if you select a plant with unopened or only partially open cyathia. You can carefully remove these structures for longer lasting color.

Do not overwater poinsettias, as these plants are sensitive to wet feet. Make sure the potting mix feels dry to the touch before watering. If you don’t remove the decorative sleeve that covers the pot, be sure there are drainage holes.

Contrary to widely reported information, poinsettias are not poisonous to our pets. The latest information from ASPCA Animal Poison Control indicates eating poinsettia leaves will induce only GI tract irritation. But as with all ornamentals and houseplants, they are not meant for our animals to eat. If you want to be on the safe side, keep poinsettias out of reach of your pets.

A more likely scenario is that poinsettias can cause a skin rash or contact dermatitis in people with sensitive skin. Contact dermatitis is caused by the plant’s milky sap, which is actually closely related to latex. Always wash your hands after handling your poinsettia.

Poinsettias naturally change color in the short days of winter in their native Mexico, but greenhouses use shade cloth to block light and trick the plants into turning color in time for Christmas. (Photo by MSU Extension/Gary Bachman)

While we enjoy poinsettias during the holidays, many don’t know some of the history of this beautiful plant. The Aztecs in Mexico and Central America cultivated this plant to produce dyes and a fever medication. In the 1820s, John Poinsett, the ambassador to Mexico and a hobby botanist, saw these native plants with their brilliant red “flowers” naturally blooming during the Christmas season.

p>In Mexico, poinsettias are known as Flores de la Noche Buena, or Flowers of the Holy Night, because of their bloom period. Poinsett sent some cuttings home, and these became the Christmas poinsettias we now enjoy. Poinsett died on Dec. 12; this day is now celebrated as National Poinsettia Day in honor of his discovery and its importance to the Christmas holidays.

Here’s a tip to help you choose your poinsettia. Regardless of color, always choose a plant in proportion to the container. You can’t go wrong with a poinsettia about 2 1/2 times taller than the container it arrives in.