Every year, people buy beautiful red, green or white poinsettias for the holidays, and once the leaves start falling off, they throw them in the trash. But there are ways for you to keep your poinsettia alive and see it bloom again next November. Just follow this monthly schedule:
In mid-November, buy a healthy poinsettia and keep it in a spot where it has bright, indirect light. It likes humidity and temperatures of about 67 degrees during the day and about 45 degrees at night.
In December, keep the plant away from drafts and fireplaces and do not over water. Too much water can cause root rot and too little water can cause the leaves to dry up and fall off. Do not let water build up in the tray either.
In January, very little care is needed. Using an all-purpose fertilizer at half-strength every other week can keep the plant looking great through January.
In February, begin half-strength fertilizing every third watering.
In March, the flower bracts will start to fade. This is a good time to put the plant into a dormant state to prepare it for the next holiday season. Prune the plant to about eight inches tall and leave one or two leaves on each branch. Cut back the watering (the top inch of soil should be dry) and do not fertilize.
In late April, start watering more frequently and fertilizing with a 12-12-12 or 20-20-20 mixture.
By late May, your plant should start to grow. Re-pot your plant in fresh soil (poinsettias like slightly acid soil).
In June, you can put your poinsettia outside. Just keep it away from winds that will dry out the soil, and keep the soil moist. Southern exposures do well as long as there is good drainage. Water every other week and use the half-strength fertilizer or slow release pellets.
In mid-July, pinch the tips back about 2-3″ if you want a shorter plant with smaller flowers. If you want a taller plant, re-pot in a bigger pot and do not use garden soil. Use a sterilized, lightweight potting mix and thin out the branches.
In August, beware of white flies and take care of the problem before bringing the plant inside. Maintain the same watering and fertilizing schedule until around mid-September.
In mid-September and October, pay particular attention to the light. Poinsettias are photoperiod sensitive, which means that their flowering is triggered by the length of time they are exposed to light. When the plant senses that the days are shorter, it starts reproduction.
Their light schedule is very strict: no more than 10 hours of light a day. Once it has been exposed to light for 10 hours, put it in a dark place (a closet or bathroom with no windows, or even a box) and then take it out in the morning and place it in a sunny, indirect light location, around 70 degrees. Repeat the process for 10 weeks.
Continue watering and half-strength fertilizing and by mid-late November you should notice the bracts forming.
Congratulations! You will have a beautiful poinsettia in time for the holidays