The poinsettia, or Christmas Star as it is known throughout Europe, is one of the very few plants that bloom during winter and the holiday season.
The poinsettia has a rich and unique history that dates back to the Aztecs. The plant is native to Central America, specifically southern Mexico and is known there as Buena Noche – Christmas Eve.
The Aztecs used the red bracts on the plant to extract a purple-red dye they used in textiles and cosmetics. They used the white sap, called latex, that secretes when stems or leaves are cut, and mixed it with other herbs to produce an external preparation to treat fevers. They called the plant Cuetlaxochitl.
The poinsettia was introduced into the United States between 1825 and 1829 by then-U.S. ambassador to Mexico Joel Roberts Poinsett. Mr. Poinsett’s passion was botany and when he first came across the bushy plant he was fascinated by the bright red colour of the plants and their unusual blooming time.
He sent cuttings back to his plantation in South Carolina, where he had several greenhouses, and to friends with botanical gardens.
Eventually a Pennsylvanian nurseryman grew the plants and was the first to sell them under the name Euphorbia pulcherrima which means “the most beautiful Euphorbia.”
The name was not one easily remembered. Therefore around 1836 the plant became to be known as poinsettia in honor of the man who introduced the plant into the U.S. and December 12 has been declared National Poinsettia Day.
The plant’s association with Christmas began in Mexico in the 16th century. The story is told of a young poor girl, Pepita, who had no gift to provide for the celebration of Jesus’ birthday. An angel encouraged the little girl to gather weeds and place them in front of the church alter.
Crimson blossoms sprouted from these “weeds” and became beautiful poinsettias.
From then on Franciscan friars in Mexico included poinsettias in their church decorations. The star patterns of the bracts are to symbolize the Star of Bethlehem and the red colour represents the blood sacrifice of the crucifixion.
Today poinsettias are a widespread Christmas tradition, for both gift-giving and holiday decorating. Many people mistake the red leaves as the flower, but the actual flowers are found in the centre of the bracts.
The bracts function as the petals and the tiny yellow flower clusters in the center of the bracts are the actual “flowers”. Ideally, look to buy plants that have these flowers intact.
Poinsettias will flower long after the holiday season if watering is continued. They will lose the bract colour if kept too dry and go into dormancy.
The plant can continue to grow. I have seen specimens that are 8-9 feet tall and are thus treated as regular houseplants.
Because poinsettias come from a warm tropical climate, they do best if the day temperature is around 21C/70F and the night temperature not below 13C/55F.
If you see brown spots on the leaves, the usual cause is that the plant has been exposed to cool or cold temperature. When I had my flower shop, I’d recommend that my customers warm the interior of their cars before the plants were transported home.
Poinsettias should be watered using warm water. The foil wrapping around the plants’ pot should be taken off periodically so the roots of the plants have a chance to breathe.
Bright light during the day is ideal; check the bottom of the container for moisture or let the soil pull away from the rim of the container before watering, then water lots!
Think of the tropics – it rains heavily for short periods, then dries out, then rains heavily again.
How often to water poinsettias depends on the size of the plant and the warmth of your home. The soil pulling away from the rim of the container test, or checking the soil moisture through the holes on the bottom of the container, are the most reliable methods.
Dropping and yellowing of the leaves are often a common problem with poinsettias, especially in the Yukon. The cause can be several things, but often the environment of the plant is too dry. They like it moist – again, remember the tropics!
Misting is one way to solve the problem, provided your home is around 20C/68F. Another reason leaf-drop occurs is that the lower leaves may not get enough light.
There’s not much we can do other than give the plant a bright location in the day. Since our days are very short at this time of the year, that may not be easy; however, the leaves will grow back as soon as the days get longer.
Keeping the plants and trying to re-flower them takes a bit of effort but the results are satisfying and beautiful.
After the holidays, remove the plastic sleeve or container surrounding the growing container and give them lots of light. By March any dropped leaves will have started to grow back.
If the plant gets tall and scraggly, the top third can be trimmed or shaped. Continue growing but stop any pruning in July.
If you have a greenhouse, especially one with supplemental heat at night, the plants can go into the greenhouse. If you don’t have a greenhouse, just continue to grow the poinsettia as a houseplant.
Fertilize it during the summer and fall growing period with a mixture of a water-soluble organic fertilizer once a week.
Poinsettias respond to long nights and short days to initiate the colour change. In the Yukon, the plants must receive 14 hours of total darkness and 10 hours of normal light for a period of 10 weeks at a temperature of about 18C/65F.
The darkness should be uninterrupted darkness. Turning on a light in an otherwise dark or empty room or in a closet may foil or hinder the process. I have known people to put the plants in dark closets and promptly forget about them!!
They need to be watered and fertilized as usual once every two weeks.
After 10 weeks, the flower initiation period is over, and the plants can be moved into a bright area of the house. The bracts will turn red in time to be enjoyed for next year’s holiday season.