How to Make a Poinsettia's Leaves Turn Red

Poinsettias can be forced to turn red.

Poinsettias, the brightly leafed tropical plants that we love at Christmas, often don't last past the holiday, but that is partly because people give up on them after the decorations come down. If you start with a healthy plant that has dark green leaves and bright yellow bracts and keep it out of cold temperatures, you can keep it as a winter houseplant, even after the holidays. Then force it to bloom red again in time for the next holidays.

Things You'll Need

• Cardboard box or other enclosure

Instructions

1. Situate the poinsettia in a sunny but cool location during the day. A location near a window that does not have a heater under it would be ideal, because, according to the University of Illinois Extension, the temperature should range from 65 to 70 degrees during the day and five degrees lower at night.

2. Put the plant in a closet or under a box for at least 13 hours a day from late September through late November. During this time poinsettias will need no more than 11 hours of light a day.

3. Keep the plant moist but not soggy. Too much water will decrease a poinsettia's flowering time, as will allowing the plant to dry out, says University of Illinois Extension, which also advises poking holes in the bottom of the decorative foil wrapper, if the plant has one.

Tips & Warnings

• You can plant poinsettias in a sunny garden space during the summer, according to Dr. T. Ombrello of Union County College in New Jersey, but bring them in before the night temperatures fall below 60 degrees.

• Give poinsettias water-soluble plant food once a month.

• Poinsettias do not tolerate hot or cold drafts wekk, according to Ombrello, so be sure the window you place it near is well-sealed.

• Avoid north-facing windows, because they do not get enough sunlight.

References

• University of Illinois Extension: Poinsettias Are Here
• Union County College: Poinsettia