Caring for Poinsettias After the
Holidays
Jeff Schalau, County
Director, Agent,
Agriculture & Natural Resources
Arizona Cooperative
Extension, Yavapai
County
During the holiday season, we see poinsettias everywhere.
Many of us buy a plant for decorative touch or as a gift for someone we are
visiting. The poinsettia industry has grown around this holiday tradition.
Today, poinsettias are one of the most important floricultural crops produced
in the United States.
Here are some hints to keep your poinsettias looking perky
and colorful well beyond the holiday season. Poinsettias thrive on bright,
sunny natural daylight; at least six hours daily is recommended. Placement near
a sunny window is ideal. To prolong the bright red of the bracts, temperatures
ideally should not exceed 70° F during the day, or fall below 65° F at night. Be sure to avoid placing the plants
near drafts, fluctuating air currents, excess heat and dry air from appliances,
fireplaces or ventilating ducts. Chilling injury will occur if poinsettias are
exposed to temperatures below 50° F. Frost will kill them.
Poinsettias do best with a moist soil condition, not too wet
and not too dry. Water the poinsettia thoroughly when the soil surface feels
dry to a light touch. The best indication of a thorough watering is when the
water begins to seep through the drain holes at the bottom of the inner pot. Be
sure to discard any excess water, as poinsettias left sitting in water may suffer from permanent root-rot damage.
It is not necessary to fertilize your poinsettias when they
are in bloom during the holiday season. However, after 6-8 weeks, a balanced,
all-purpose household plant fertilizer mixed ½-strength will help maintain the
rich, green foliage color and promote new growth. Repeat once more in another
6-8 weeks.
Here are some tips for those that would like to keep their
poinsettia growing until next holiday season. At the end of April or early May,
when the bracts age and begin to turn a muddy green, cut the plant back to
about 8 inches. The amount you cut from the top will depend on the shape of the
plant. After you cut the plant back, it will probably look rather stark, with bare branches and bluntly cut woody
stems. Keep the plants near a sunny window. You may place your plants outdoors
where they can bask in the warmth of summer when the outside night temperatures
are warmer. Continue to water the plants regularly during the growing period.
Fertilize every 3 to 4 weeks throughout the spring, summer and fall months with
a well-balanced fertilizer mixed ½-strength.
Around June 15th you may wish to transplant your poinsettias
into larger pots, about 2" to 4" bigger than the original inner pot.
Use a soil mix that incorporates a considerable amount of organic matter such
as peat moss. Immediately after transplanting, be sure to water thoroughly.
The plants will naturally come into full bloom during
November or December depending upon the flowering response time of the
particular variety. This can be tricky to do outside of a controlled greenhouse
environment, because any stray artificial light such as that from a street
light, pool light or household lamp could delay or halt the re-flowering of the plants.
Starting October 1, the plants must be kept in complete
darkness for 14 continuous hours each night. Moving the plants to a dark room
or placing a large box over them can accomplish this. During this period, the
plants require 6 to 8 hours of bright sunlight and night temperatures between
60° and 70° F. If the temperature is too high or too low, the setting of the flower buds may be delayed or halted. The
blooming process may also be delayed or disrupted by any stray light that may
shine near the plants during the critical darkness period. Keep this up for 8
to 10 weeks for full color development. If this sounds like a lot of work, it
is. It certainly gives me a healthy respect for the nursery industry. If all
this sounds like too much work, then support the horticulture industry by
purchasing new plants each year.