by Sandy Feather
Penn State Extension
Q: I received a lovely poinsettia from my son and would like
to keep it for next Christmas. How can I care for it and get it to
bloom at the right time?
A: During the holiday season, keep your poinsettia in a sunny
location, but avoid hot afternoon sun. Do not allow its leaves to
touch cold window glass. Your poinsettia will require more frequent
watering in the sun. What people think of as poinsettia flowers are
really leaves called bracts; the true flowers are the small,
yellowish structures in the center of the bracts.
Do not place your poinsettia where it will be subjected to cold
drafts; they are tropical plants and can be injured by temperatures
below 50 degrees. Keep the soil evenly moist, never sopping wet.
Remove decorative foil from the pot when watering; you can replace
it once water stops running through the drainage holes, or punch
holes in the foil to allow water to drain out. Otherwise, it will
hold water around the roots and cause them to rot.
Fertilize every two to three weeks with a complete water-soluble
fertilizer at half-strength while bracts are showing color. Products
such as Miracle-Gro (15-30-15) or Peters 20-20-20 are fine.
The bracts generally fade in late March or April. Care for it as you
would any other houseplant. Keep it in a sunny location and water as
needed to keep the soil from drying out. Quit fertilizing once the
bracts fade. Cut the stems back to 6 to 8 inches. It's a good idea
to wear rubber gloves and long sleeves when cutting back a
poinsettia because the milky sap can irritate your skin if you are
sensitive to it.
Reduce watering so that the top inch or two of soil dries between
waterings, but never allow the plant to wilt completely. This gives
your poinsettia a slight rest period before it grows again.
In early June, when your poinsettia puts on strong new growth, repot
it into one a size larger than its current container. If you jump up
too many container sizes, there will be too large a volume of soil
around the poinsettia's root system, possibly causing root rot.
Once it is transplanted, place it back in a sunny window. Your
poinsettia can also spend the summer outside in a protected
location. An area that receives full morning sun and shade from the
hot afternoon sun is ideal.
Fertilize every other week with a complete water-soluble fertilizer.
To encourage bushy plants, pinch the new growth back by an inch or
two in July. You can pinch it back again in late August if it is
growing very vigorously. If your poinsettia is outside, be sure to
move it back indoors before night temperatures fall below 60
Inspect your plant regularly for signs of insects. Whiteflies are
the most common pest of poinsettias. If a cloud of white insects
hovers when the foliage is disturbed, they are likely whiteflies.
Repeated applications of insecticidal soap should take care of the
problem. Insects should be less of a problem on indoor plants.
Getting your poinsettia to bloom for next Christmas requires a
little planning. Poinsettias bloom in response to long nights. You
should start providing prolonged nights the last week of September
or the first week of October in order to have it in bloom for
Move your poinsettia to a closet or cover it with a box or basket
every night; leave it in place for 14 hours. This must be done
nightly for eight to 10 weeks. The dark cycle cannot be interrupted,
not even briefly, or it will delay flowering.
Move your poinsettia to a sunny location during the day. Once the
small bracts begin to appear, you can leave it in its normal place
and stop subjecting it to darkness.