AGRICULTURAL EXTENSION SERVICE
T. J. SHEEHAN AND R. D. DICKEY
Assistant Ornamental Horticulturist and
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. Poinsettias
are particularly prized for their display of color during the
The poinsettia, Euphorbia pulcherrima, is a member of the
Euphorbiaceae or spurge family. Jole 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 but 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-
2. Indianapolis Red-Red
3. Albert Ecke-Red
4. Oak Leaf-Red
5. Mrs. Paul Ecke-Red
6. Ecke White-White
Poinsettias usually root readily from hardwood cuttings of
wood obtained (Fig. 2) at time of pruning back. Mature and
healthy branches pruned out can be made into cuttings about a
foot long and rooted in a propagating unit or in the yard where
you want the plant to grow. Home gardeners can root cuttings
easily by punching holes in desired locations, inserting three
quarters 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 also can be made from branches from June to
September. These can be rooted under mist or in any propagat-
ing unit. Since the cuttings are tender, it is important that the
humidity remain high around the cuttings. Covering the unit
with polyethylene film as recommended in Circular 148 will be
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.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida,
Florida State University and United States Department of Agriculture, Cooperating
M. 0. Watkins, Director
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, three 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 about 12 inches
long; softwood (right) 4 to 6 inches long.
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 four 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 Oc-
tober 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. If the night temperatures are much above 70' F. during
bud-forming periods, usually about October 1-10, the bracts will
be slow to form or may not form at all. The best flowers develop
when the night temperatures range from 60 to 620 F. Growth
will be slow and flowering delayed, leaves may turn yellow and
bracts shed if temperatures drop much below 600 F., especially
if temperature has been high.
The poinsettia is very sensitive to cold and many years the
plants are frozen before they have had a chance to bloom. Freez-
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 one
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 two 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 with copper A or bordeaux mix-
ture to prevent further spread.
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.