A reader of this column recently sent me an email asking about the care of poinsettias.
When many people think of the holidays they think of the poinsettias. Poinsettias are named after Joel R. Poinsett who was the United States ambassador to Mexico in the 1820’s. Poinsett brought some plants (I wonder what the common name was then!) back to the United States and propagated them in his greenhouse.
This member of the Euphorbiaceae family is presently grown in the United States by professional growers from cuttings from the Paul Ecke Ranch in California. There are actually over 100 varieties of poinsettia but only are few types are sold by nurseries. Most people prefer the red followed by the white then the pink. The showy part of the poinsettia is really a display of bracts, which are modified leaves. The true flower shows up in the middle and is small and yellow in color.
Keep your poinsettia moist and in bright light. Water it only when the soil surface is dry. You might want to remove the colored wrapping that may have been placed around the pot when you water the plant to insure good drainage and to keep the poinsettia from sitting in a pool of water. If you prefer, you can replace this colored foil when you return the poinsettias to the display area. Moving the plant to a cooler room at night prolongs its bloom. Readers of this column probably already know from my treatment of other plants that I have yet to actually move any of my plants at night!
A problem that sometimes occurs with poinsettias is leaf drop. This is usually caused by sudden temperature changes. Poinsettias don’t like to be placed on fireplaces or near doors that open to the outside. You shiver or sweat to maintain body temperature. Poinsettias drop leaves to prevent water loss.
Many people in this part of the country treat poinsettias as a disposable plant much like an annual. The poinsettia is actually a perennial. I have seen it growing in Mexico and in Tanzania to about 10 feet tall. To get your poinsettia to bloom for the December holidays, growers had to begin preparing them back in October. Poinsettias are short-day plants. This refers to the fact that they flower approximately 10 weeks after the daylight hours shorten to 12 hours or less each day. Growers keep the plants in total darkness for 12 to 14 hours each day to insure bloom.
I think that anyone interested in plants should try at least once to get poinsettias to bloom again the next year. Only you can decide if this is a worthwhile endeavor to pursue. I have done this successfully two different years but lately I have chosen to recycle the plants as compost. To get your poinsettia to rebloom next year you need to keep it in bright light. I carefully repotted mine after the holidays in potting soil in a new pot with drainage holes. When it was time to plant the annuals outside I moved the poinsettia to our front porch, which faces south. In late summer I pruned the poinsettia back to make it produce more shoots. In September I brought the poinsettia inside. Now this is the “fun” part. I put a box over the poinsettia each evening for 14 hours. If any light strikes the plant during the 14 hours dark period it won’t flower. In the day time the plant is kept in bright light. I know you are thinking “What happens when they grow in the wild?” Well in the wild the day length gradually shortens but not as much as here in the northeastern United States. Also the temperature doesn’t fluctuate as drastically as it does here.
After 8 to 10 weeks you should notice flower formation. Put into bright light. Enjoy!
You have probably heard that poinsettias are poisonous. This is based on a story about one woman who supposedly ate a leaf. It is not based on science. You weren’t planning on eating it anyway were you?