COLLEGE STATION — Poinsettias in the traditional red and a host of new colors can be found in most holiday decor, adding much to brighten the seasonal displays.
But the popular plant can suffer during the holidays if not properly cared for, according to a Texas A&M AgriLife Extension Service plant pathologist.
“There are ways to care for poinsettias to keep them looking good and to avoid some of the common diseases that affect them,” said Dr. Kevin Ong, AgriLife Extension plant pathologist and director of the agency’s Plant Disease Diagnostic Laboratory in College Station.
One of the most common diseases of poinsettias is pythium root rot, he said. When the roots are attacked by this disease, they turn brown and mushy instead of the usual healthy white color.
“Poinsettias are shipped in protective sleeves to prevent damage to them,” Ong explained. “These sleeves may not have drainage holes, so if water is allowed to stand in them, the roots can begin to rot if the pathogen attacks.”
With rotted roots, he said, the healthy green leaves turn yellow and drop off of the plant.
Improper watering can also cause other problems for poinsettias, he noted.
“A plant that is stressed and has not been watered correctly may get spots or blotches on its lower leaves,” Ong said. “If this happens, remove those leaves and begin watering the plant correctly.”
He said preventing a disease is better than trying to cure a sick poinsettia. Ong offered these seasonal poinsettia tips:
- A white Christmas is not poinsettia-friendly. Poinsettias are originally from the tropics, so keep them indoors if the temperatures are going to be under 60-70 degrees. A cold poinsettia will turn yellow and drop its leaves.
- Drink in moderation. Poinsettias will drown or get sick if they get too much water. Only when the soil feels dry should a poinsettia be watered.
- Diet control. Poinsettias that fill up on a fertilizer buffet will start to look peaked. Feed a poinsettia after the holidays, when everyone else is dieting, if you want to try to keep it alive.
For more information about plant diseases, see http://plantclinic.tamu.edu/.