Things You'll Need
How to Keep a Poinsettia Going After Christmas. If your poinsettia is still alive past New Years Day, it has passed through the shock of being moved from the greenhouse into your home. Odds are good that it will continue to grow for next year's holiday celebration. Here's what you need to do.
Continue to water your poinsettia, keeping the soil moist, but not wet, at all times. Keep the plant away from drafts caused by opening doors or heater vents.
Set the poinsettia outdoors once night temperatures average 55 degrees F or above.
Transplant the poinsettia into a larger pot. Use fast-draining potting soil rich in organic matter.
Cut the poinsettia back to about 8 inches in height in late March or early April. By the end of May you should see vigorous new growth.
Prune during the summer to keep the plant bushy and compact. Do not prune after September 1.
Keep the plant in indirect light or filtered sun.
Fertilize every 2 to 3 weeks with a complete fertilizer.
Move the plant into a closet each night, starting in October, for 14 hours, making sure it receives no light at all; move it into the light each morning for a maximum of 10 hours. Poinsettias bloom only when they experience long nights.
Continue this procedure every day for 10 weeks and you can have poinsettia blossoms for next Christmas.
The secret to growing poinsettias is to provide constant moisture to the roots. Don't, however, allow the plant to sit in water.