By Ken Johnson
Now that the holidays are winding down have you have been wondering about what you should do with that poinsettia plant? If you take good care of your plant they can retain their color for several months. After it is done blooming it is possible to get it to bloom again next season, with a little work.
Cut the plant back after it is done blooming to within 4 to 6 inches of the soil, this will help encourage new growth. If you wish to re-pot the plant now is the time to do that as well. When the plant starts to produce new growth place it in a sunny window and treat it like any other house plant, watering when dry and occasionally fertilizing with a dilute fertilizer.
In late May or early June move your poinsettia outdoors, gradually exposing it to direct sun over the course of a week or two to allow it to acclimate to the outdoors. After doing so dig a hole to place the pot in in an area that receives 6 to 8 hours of direct sunlight with some shade in the afternoon. Occasionally turn the pot to prevent your poinsettia from rooting through the bottom holes of the pot. If you can’t put your poinsettia pot in the ground, you may need to water it more frequently. If you don’t want your plant getting too leggy make sure to pinch off the shoot tips, choose tips that have two or three fully expanded leaves below them. Do this every three or four weeks, until mid-August, to keep the plant compact and bushy. Make sure to regularly water your poinsettia and fertilize every couple of weeks.
Before night temperatures get down to 55-60°F degrees its time bring your poinsettia back inside and place it in a sunny window. Poinsettias are short-day plants this means they grow vegetatively during times where there are long days and will produce flowers when exposed to short days or more specifically long nights. In order to get your plants to flower for Christmas they will need to be in complete darkness from 5 pm to 8 am from the end of September/early October until the bracts (the red leaves) develop good color, usually in the beginning or middle of December. To do this place your plant in a closet or cover it with a box during the night. During the day it should be back in the sunny window. Keep doing this until the bracts are almost fully expanded. Try to make sure temperatures don’t go below 55°F at night and over 70°F during the day.
With a little work you should be able to keep your poinsettia going years to come. For more information about poinsettia care check out the Poinsettia pages at http://urbanext.illinois.edu/poinsettia.