One of the research greenhouses at the University of Maine’s Cooperative Extension Service is decorated for the holidays with one of the most popular plants sold in the United States.

While poinsettias are a spectacular way to embellish home and office this time of year, their presence at the greenhouse is serious business. For the past several months, the plants have been monitored for insects and diseases in the climate-controlled greenhouse. No one wants to buy a poinsettia with damaged leaves.

“We’re recording everything,” said Dr. Jim Dill, pest management specialist with the University of Maine Cooperative Extension Service. “There are a number of factors that can affect the growth and bloom time of these plants.”

Information is gathered and communicated to the few greenhouses that are growing this holiday symbol.

“There are only about eight wholesale poinsettia producers in the state,” said Dill. “They have a big investment in plants and want to know what to expect every step of the way.”

In fact, these very greenhouses are the ones that donate poinsettia plugs to the Extension Service research project.

Dill and ornamental horticulturist Dr. Lois Berg Stack have been growing poinsettias and recording data for several years. Plants are regularly photographed and even videotaped. They want to be able to tell growers, “This is what your plants should look like in October, and this is what they should look like in November.” Greenhouse growers want a healthy, spectacular plant that is colored up and ready for sale at peak buying season.

Even professional researchers can be perplexed once in a while, though. One year, as the holidays approached, the poinsettias in the greenhouse were vigorous and healthy, but they weren’t turning red. Researchers were stumped until one evening when Dill returned to the office late at night and realized that a light from a previous project was on a timer and coming on when everyone was gone for the day. Poinsettias, it turns out, are very sensitive to day length, and the light disrupted them enough that they were not turning color. When the problem was corrected, the beautiful colors developed — but after the holidays. It’s information like this that is vital to growers who depend on this seasonal crop.

The poinsettias in the Extension Office on College Avenue in Orono are not for sale. They are donated to area charities — ’tis also the season for giving.

Lisa Colburn is writing a book about gardening practices in Maine called “The Maine Garden Journal.” She may be reached at info@mainegardenjournal.com or 866-3861.

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It’s a fact

• Poinsettias are tropical plants native to Mexico and Central America.

• Poinsettias are NOT poisonous, but research indicates that the white latex sap is an irritant and should not be eaten.

• Poinsettia flowers are small and yellow. The colorful bracts (actually modified leaves) surround the flowers and are found in reds, pinks, whites and a combinations of all three.

• There are more than 100 varieties of poinsettias.

• The poinsettia was named after Joel Poinsett, the first U.S. ambassador to Mexico.

• There is much controversy about how poinsettia is pronounced. Point-SET-ee-ah is the preferred pronunciation; however, some people pronounce it as though it has no letter “i” at the end — point-SET-ah. Both are acceptable.

• Poinsettias are in the spurge family. The botanical name is Euphorbia pulcherrima.

• pulchritude n. physical beauty – pulchritudinous adj.