Re-blooming Poinsettias
December 19, 2005
  • /Crop Sciences
URBANA-Poinsettias, a popular Christmas season gift plant, can be re-bloomed, but unless a year-long schedule of care is provided, the results are usually not very good, said a University of Illinois Extension horticulture educator.

"If you were to ask the question, 'What flowering plant reminds you of Christmas?' the overwhelming answer would be the poinsettia," said Greg Stack. "Then, if you asked the question, 'What flowering gift plant do most people most often try to re-bloom?' again poinsettia would be the answer of choice."

But, as he noted, the plants are difficult to re-bloom. Stack recommends that those wishing to keep and re-bloom poinsettias follow some guidelines.

"Many of the newer cultivars of poinsettia will keep their leaves and colorful bracts for a very long time – well past the holiday season. Once you are done enjoying your plant, start to allow the soil to dry gradually. This will cause the leaves to drop," he said. "When most of the leaves have dropped, place the plant in a cool location such as in a basement on a window ledge where temperatures are around 60 degrees. Water just enough to keep the stems from shriveling but not enough to cause the plant to start growing. This is the resting period."

In late April or early May, Stack recommends cutting back the plant to 3 inches, watering it well and placing it in a well-lighted, warm location. New growth should appear. Water whenever the soil starts to dry. Fertilize with a general-purpose liquid fertilizer about once every 2 weeks.

"When all danger of frost is past, place the plant outdoors," he said.

"You can place it on your deck or porch or sink the pot into the ground in the garden. Continue to water and fertilize as needed. To prevent the plant from getting too tall, pinch new shoots when they are about four to six inches long. If the new shoots grow another five inches, pinch again. Don’t pinch after September 1."

When outdoor temperatures start to get cool, bring the plant indoors to a bright sunny window. Beginning about September 25th, poinsettias need complete darkness from 5 pm to 8 am each day in order to initial blooms and the red bracts. To accomplish this, put the plant in a closet or under a cardboard box each night at 5 pm. During the day, put the plant back in the sunny window. Water and fertilize regularly during this time.

"If all goes well you should start to see red bracts develop in late November. The bracts that do develop may not be as big as the ones you see on florist poinsettias due to the less-than-ideal indoor growing conditions," he said.

"But who cares? You have taken on the challenge and got your plant to re-bloom. You can now say to your guests, 'How do you like the poinsettia I grew?'"

For those not wanting to take on the re-blooming challenge, Stack recommended visiting local greenhouses or florists who can supply plenty of top-quality Christmas poinsettias.