Title: Poinsettia culture
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Permanent Link: http://ufdc.ufl.edu/UF00084388/00001
 Material Information
Title: Poinsettia culture
Series Title: Poinsettia culture
Physical Description: Book
Creator: Sheehan, Thomas J.
Publisher: Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
 Record Information
Bibliographic ID: UF00084388
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 232333783

Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

Revision ox no.
Circular 172E January 1971



Ornamental Horticulturists
Florida Agricultural Experiment Stations

Poinsettias are predominantly greenhouse grown as pot
plants for Christmas in most of the United States, but in Florida
they are largely utilized as colorful landscape shrubs. Poin-
settias are particularly prized for their display of color during
the Christmas season.
The poinsettia, Euphorbia pulcherrima, is a member of the
Euphorbiaceae or spurge family. Joel R. Poinsett of Charleston,
S. C., United States Minister to Mexico, introduced poinsettias
into the United States about 1830. The flowers (Fig. 1) are in-
conspicuous, the showy parts being leafy bracts. The color of
the bracts varies from red to pink to white, depending on variety.
It is classed as a shrub and may attain a height of 12 or more feet.
Many varieties of poinsettias have been developed for adapt-
ability to forcing as greenhouse pot plants. However, the follow-
ing are considered best varieties for outdoor culture in Florida:

1. Henrietta Ecke--Fireball-- 9. Ecke White--White
Double red 10. Pink--Pink
2. Indianapolis Red--Red 11. Mikkelpink-Pink
3. Albert Ecke--Red 12. Stoplight-Red
4. Paul Mikkelsen--Red 13. Snowflake-White
5. Oak Leaf--Red 114. White Cloud--White
6. Mr s. Paril cke-k ', \15. Annette Hegg--Red
7. Ec t.R d 16. C-l--Red
8. Rel Ivet--Red

Poinsettias usually root easily rom hardwood cuttings of
wood obtained (Fig. 2) at time of pruning back. Mature and
healthy branches pruned out cant e made into cuttings 6 to 12
inches long and rooted 4i a propagating unit or in the yard
where the plants are to gr-6w. Home gardeners can root cut-
tings easily by punching holes in desired locations, inserting
% of each of the woody cuttings into the soil and pressing
the soil firmly around the base of the cutting. The soil should

be kept moist at all times. Mulches around the cuttings will aid
in maintaining favorable moisture, soil temperatures and weed-
free conditions for rooting and growth. Tip or softwood cuttings
of semi-hard wood 4 to 6 inches long also can be made from
branches from May to September. These can be rooted under
mist or in any propagating unit. Since the cuttings are tender,
it is important that the humidity remain high around the cut-
tings. Covering the unit with polyethylene film will be ideal.

Fig. 1.-The showy part of the poinsettia, usually considered the flower,
consists of the colored bracts.

This plant can be found growing quite satisfactorily in a
wide range of soils, including sand, muck, marl, rocky soil, and
clay. In spite of its wide adaptability, the poinsettia responds
well to good care.

(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperuting
Joe N. Busby, Dean

A complete fertilizer in which the nitrogen, phosphorus and
potash are in a 1-1-1 ratio, such as a 6-6-6 or 8-8-8, is satisfac-
tory for poinsettias. (6-6-6 should be used at the rate of 11/2
pounds per 100 square feet per application.) Usually, 3 ap-
plications per year are recommended-the first when growth
starts in the spring, the second in June and the last in late fall
after the bracts have set. This last application promotes large
bracts with good color and aids in promoting root growth during
the winter months. Occasionally, a fourth application will be
required in mid-summer if the early summer application is fol-
lowed by extremely heavy rains.


Fig. 2.-Poinsettia cuttings. Hardwood (left) should be from 6 to 12 inches
long; softwood (right) 4 to 6 inches long.

Fig. 3.-Unpruned poinsettia (left) and pruned plant (right).

The best way to handle poinsettias is to prune them back
in late winter or early spring after blooming is over or after the
danger of frost has passed. They should be cut back to within
12 to 18 inches of the ground unless they have been frozen below
this point, in which event they should be cut back to the "live"

A compact plant may be obtained at flowering time, rather
than one with a few long, unbranched canes, if the plants are
pruned several times during the growing season (Fig. 3). The
new growth, after it is 12 inches long, should be cut back, leav-
ing 4 leaves on each shoot. This operation should be repeated
every time the new growths develop until about September 10.
Pruning in this manner will produce a nice compact plant with
many flowers. Pruning after September 10 may interfere with
flowering, as these plants set their buds soon after October 10.

A plant will be seen frequently near a house or on a front
lawn that is not flowering when all other plants in the neighbor-
hood are in full bloom. Since the time of bloom of the poinsettia
is influenced by the length of day, this occurrence is readily ex-
plained. As the days become short in the fall the plants set their
flower buds about October 10 in Florida. However, plants can be
prevented from flowering by artificially extending the day length
with electric lights. This condition may occur when a plant is
growing near a street light or around the house where it receives
light from a window or door. In such cases, either flowering will
be markedly delayed or the plant may not flower at all.

Weather conditions also will have an effect on flowering.
Periods of dark, rainy weather in late September and early Octo-
ber often will shorten the days sufficiently to cause the plants
to set buds and flower early. Commercial growers give the plants
supplemental light under these conditions to prevent early bud
set and flowering.

Temperature also can be a limiting factor in flowering poin-
settias. High temperatures, 70 to 800F., in September and Oc-
tober can delay flowering and thus coloring of the bracts.

The poinsettia is very sensitive to cold and many years the
plants are frozen before they have had a chance to bloom. Freez-

F'~ I i1~nnE

ing is particularly severe in unprotected locations of the northern
sections of the state. Therefore, plantings should be confined
to warmer parts of central and southern Florida.
Poinsettias may be used as cut flowers if treated to coagulate
the milky sap and reduce wilting. This may be accomplished by
immersing the cut end of the stem in hot water for about 1
minute and then placing immediately in cold water. Use care
to prevent steam from the hot water from damaging the flowers.
An alternate method of treatment is to singe the cut end of the
stem over a flame for a second or 2 and then place the stem in
cool water. Poinsettia flowers should be cut at least 18 to 24
hours before they are to be used in arrangements and should be
stored in a cool place and away from drafts.
Poinsettia scab often is a problem in some areas, especially
on double red varieties. Scab appears as conspicuous, raised
lesions or cankers on the stem or cane. The lesions are usually
circular but in advanced stages they combine to form large, ir-
regular areas. In severe cases the plant will lose its leaves when
the stem is girdled by the cankers. Cankers may appear also as
spots on the leaf petioles.
Scab is most prevalent in the summer and scab-infected
branches should be pruned and burned as soon as they are noted.
The plants should be sprayed weekly with Maneb or Captan as
long as the disease is a problem.
Plants may be attacked by fungi causing both root and stem
rots, but the stem rot that starts at the ground line is the most
prevalent and troublesome. When this condition becomes evident
it is usually too late to save the plant. The diseased plant should
be removed and the area treated with one of the soil fumigants
before replacing it with another poinsettia. Soil drench of a
fungicide is also used by some.

First Printing November 1957
Second Printing March 1960
Third Printing May 1963
Fourth Printing February 1965
Fifth Revision January 1971

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