From: kellogg@ymir.ucdavis.edu (Louise Kellogg)
Newsgroups: rec.gardens
Subject: Poinsettia
Date: 9 Oct 92 21:49:53 GMT
Organization: UC Davis
Originator: kellogg@ymir.ucdavis.edu

Someone asked how to force poinsettias to bloom in time for the
holidays.  Last year, there were a number of questions about
poinsettias right after New Year, and Bob Batson posted this answer.
I saved it, thinking it would come in handy; hope Bob and others don't
mind if I repost it.  I only wish I'd reread it this summer before
sunburning my own poinsettia.
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            HORTICULTURE FACTS SHEET MF-521 December 1981
                    COOPERATIVE EXTENSION SERVICE
                       KANSAS STATE UNIVERSITY
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                      HOME CARE OF POINSETTIAS

  Red poinsettias are the traditional Christmas flower in the United
States and throughout much of the world.  Poinsettias
(poin-set-ie-uhs) provide a cheerful Christmas spirit and their bright
color goes well with the Christmas tree and other decorations in the
home and office.  White, pink and marbled colored plants are also
available although not as popular as the red varieties.
  The showy, colored parts of the plant, commonly called flowers, are
actually modified leaves or bracts.  The inconspicuous true flowers
are located in the center of each whorl of bracts.  They are green,
have no petals and bloom with yellow flower parts and pollen.

Winter Care in the Home

  Place your poinsettia in a sunny window or the brightest area of the
room but don't let it touch cold window panes.  The day temperature
should be 65-75 degrees F. and 60-65 degrees F. at night.  Do not
place on top of a TV set because it gets too warm while it is
operating.  Temperatures above 75 degrees F. shorten bloom life and
below 60 degrees F. cause root rot.  Move plants away from windows at
night or draw drapes between them.
  Examine the potting soil daily.  Never let the plant wilt or it will
lose its leaves.  When the soil becomes dry to the touch, water the
plant with lukewarm water until some water runs out of the drainage
hole, then discard the drainage water.  Poinsettias do not like "wet
feet."  Repotting is not necessary during the winter.

Spring Care in the Home

  Most dealers sell only the better varieties of the new long lasting
flower types.  Many of these plants hold their blooms until May when
they can be cut back and set outdoors after frost.
  As days lengthen and light intensity increases in March, side shoots
often develop below the bracts.  The old leaves and stems can be
removed above this new growth.  If all the old leaves have fallen and
the bracts have faded, the old stems may be cut back to six inches
above the soil.
  The plants may also be repotted at this time with a commercial
potting soil or a mixture of 1 part soil, 1 part sphagnum peat and 1
part sand.  If the plants were grown single stem (non-branched with
several plants per pot), it is best to discard them.  These cultivars,
such as the Ecke C-1's, do not branch very well and will not form
attractive plants the second year.  Reduce watering frequency in
proportion to the amount of foliage removed from the plant.
  Poinsettias can be grown indoors as foliage plants in summer or
moved outside whichever is most convenient.

Summer Care Outdoors

  When frost danger ends in May poinsettias may be grown outdoors. 
Choose a wind protected, sunny location with some protection from
midday and afternoon sun.  Sink the pot to the rim in a well-drained
soil.  Fertilize monthly according to directions with a houseplant
fertilizer.  Check water needs frequently because the soil can dry out
quickly in summer.
  Between May 15 and August 1, cut off the tips of the plants
occasionally to get a shorter, bushier plant with more branches.

Fall Care and Re-blooming in the Home

  Bring the plant indoors September 1 and place near the sunniest
window.  Beginning October 1, the plant must receive 14 consecutive
hours of uninterrupted darkness each night but must also get bright
light during the day.  Poinsettias bloom naturally by Christmas if
exposed to the normal period of darkness and daylight after October 1
provided the dark period is not interrupted by turning on the room
lights at night.  Street lights shining through room windows may also
delay bloom.
  If the room is used at night, protect the plant from light by
placing it in an unused closet or by covering with a cardboard box
(tape the seams) from 5:30 every evening until 7:30 the next morning. 
The night temperature during the dark period must be between 60-65
degrees F. while flower buds are being formed, or bud set may be
delayed or terminated.
  Plants must receive bright sunlight during the day for good color to
develop.  An artificial light source is often required to supplement
low fall and winter sunlight.  Fertilize every other week and keep the
soil from becoming too dry.  Plants need extra nourishment while being
forced into bloom.
  After the bracts show full color, usually by Thanksgiving, the dark
treatment is no longer necessary.  The key ingredient to producing a
quality plant is good light during day, which is often lacking in
homes and offices, and 14 hours of total darkness during bud set.  If
the plant that you grow does not suit your standards,
green-house-grown plants are on the market by this time.

Summary of Poinsettia Care

* During winter place plants in brightest area of the home
* In summer some protection is needed from direct midday and after-
  noon sun
* Day temperature should be 65-75 degrees F.
* Night temperature should be 60-65 degrees F.
* Protect from drafts of hot or cold air
* Move plants away from widows during winter nights
* Keep soil moist but not soggy wet
* Water when soil becomes dry to the touch
* Do not let plant wilt
* Use lukewarm water
* Discard drainage water
* Fertilize monthly with houseplant fertilizer
* Prune plants in spring and summer
* Bring plants inside by September 1
* Begin dark treatment October 1

History of Poinsettias

  Poinsettias have a fascinating history and tradition.  Poinsettias
are actually woody shrubs native to Taxco, Mexico where they grow wild
outdoors to a height of 10 feet.  The Aztec Indians of Mexico
cultivated and regarded them as a symbol of purity before Christianity
came to the western hemisphere.  They also made a reddish purple dye
from the bracts and used the milky sap to counteract fever.  
Franciscan priests settled near Taxco during the 17th century and
began to use the flowers in their nativity processions because of its
appropriate holiday color and blooming time.   Poinsettias were
introduced into the United States in 1825 by Joel Robert Poinsett. 
While serving as the first United States ambassador to Mexico, he
discovered the wild poinsettias growing on the hillsides near Taxco. 
Poinsett sent plants to his home greenhouses in Greenville, South
Carolina and then began giving plants to botanical gardens and
horticultural friends.  A nurseryman friend in Philadelphia started
the first commercial propagation and sales from some of Poinsett's
plants.  These wild plants lasted only a few days in the home.   The
poinsettia industry was pioneered and developed by the Ecke family of
California in the early part of this century.  During the mid-`50's
plant breeding research was started and led to many of our current
improved varieties (cultivars).  Today's poinsettia is a
free-branching hybrid plant with larger, longer-lasting bracts.

Selecting Your Poinsettia

  Choose plants that have clean, healthy, dark green leaves and
colorful bracts.  Be sure to check the underside of the leaves for
insects.  Avoid plants with missing leaves or bruised, broken or
spray-damaged leaves.  Plants shedding yellow pollen are over-mature. 
Healthy plants last longer and are worth the extra price.
  On a cold day (below 40 degrees) wrap the plant and pot in paper for
the trip home and purchase at end of the shopping trip.  Even a slight
chill or draft can cause the leaves to drop later on.  Unwrap the
plant as soon as you get home and place it in bright light away from
cold or hot air drafts.  Pierce the foil at the bottom of the pot for
drainage.  Water with lukewarm water if the soil is dry.
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For further information, please contact either your local county or
state U.S.D.A. cooperative extension agent.
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Bob Batson
bob.batson@p3.f322.n280.z1.fidonet.org
 * Origin: From the north forty in Kansas, USA! (1:280/322.3)
Newsgroups: rec.gardens