Citation
Gerberas for Florida

Material Information

Title:
Gerberas for Florida
Series Title:
Florida Cooperative Extension Service Circular 527
Creator:
Tjia, Benny Oen Swie
Affiliation:
University of Florida -- Florida Cooperative Extension Service -- Institute of Food and Agricultural Sciences
Place of Publication:
Gainesville, Fla.
Publisher:
Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida,
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Agriculture ( LCSH )
Farm life ( LCSH )
Farming ( LCSH )
University of Florida. ( LCSH )
Agriculture -- Florida ( LCSH )
Farm life -- Florida ( LCSH )
Spatial Coverage:
North America -- United States of America -- Florida

Notes

Funding:
Florida Historical Agriculture and Rural Life

Record Information

Source Institution:
Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location:
Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management:
All rights reserved, Board of Trustees of the University of Florida
Resource Identifier:
08840377 ( OCLC )
028527761 ( ALEPH )

Full Text


Circular 527

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B. Tjia and R. J. Black


Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences
University of Florida, Gainesville / John T. Woeste, Dean for Extension


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Dr. Tjia and Dr. Black are Associate Professors, Ornamental Horticulture De-
partment, IFAS, University of Florida, Gainesville 32611.








GERBERAS FOR FLORIDA
B. Tjia and R.J. Black
Gerbera or Transvaal daisy (Gerbera jamesonii Bolus ex. Hook
f.) is a flowering perennial which belongs to the Compositae family.
Recent introductions of new hybrids have resulted in a resurge in
their popularity. Gerberas can be used in landscapes as bedding
plants for borders and flower beds or as cut flowers for table ar-
rangements.
Gerberas are native to Transvaal, South Africa, where they
grow in full sun. They will tolerate 30F (-1 C) without adverse ef-
fect if protected from frost. Plants will overwinter in central and
north Florida in areas where prolonged hard freezes are not ex-
perienced.
Gerberas usually begin blooming when plants are 12 inches
(30.5 cm) tall or taller. Leaves are long, slender, pubescent on the
under surface and pinnately lobed or parted with leaf blades 5 to
10 inches (12.7 to 25.4 cm) long and 2 to 4 inches (5.1 to 10.2 cm)
wide. Each crown possesses numerous leaves and flower stalks
with plants eventually forming a dense clump.
Hybrid gerbera varieties cloned through tissue culture are
uniform, have long-lasting flowers with thick peduncles that are
not light sensitive, hence flowers remain open in the dark, lend-
ing themselves to indoor use in flower arrangements.
Flower Colors and Forms
Gerbera flowers often measure 7 inches (17.8 cm) across and
range in color from light to dark yellow, orange, pink, brilliant
scarlet and deep red with some clones having flowers with brown
or dark centers (eyes). Flower forms can be divided into five
distinct groups (Figure 1).
Single Singles have a row of nonoverlapping petals (ray
florets) with a green center (disc florets). These are the most com-
mon gerberas on the market.
Double or Duplex These have a double row of overlapping
petals with a green, black, or dark red eye.
Crested Doubles These doubles contain two rows of overlapp-
ing petals with one or more inner rows of shorter petals with a
green, black, or dark red eye.
Full Crested Doubles These have solid overlapping rows of
petals with an inner row diminishing in size, covering the eye en-
tirely.
Quilled Full Crested Doubles This type possesses solid
overlapping rows of split petals, having a fine textured ap-
pearance.


























Single
Figure 1 Gerbera Flower Forms


Double or Duplex


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Crested Double


Full Crested Double




























Quilled Full Crested


Double


Planting and Care
Gerberas grow best in well drained, sandy soils amended with
organic matter for nutrient and water retention. One to two
inches (2.5 to 5.1 cm) of peat or other organic material can be in-
corporated into the soil prior to planting. Dolomitic limestone at a
rate of 3 pounds per 100 square feet (1.5 kg/10m2) also should be
incorporated prior to planting.
Small plants (seedlings) can be purchased in small compart-
mentalized trays in early spring from garden supply stores, chain
stores and local nurseries in north Florida and in early fall in cen-
tral and south Florida. These small plants can be transplanted
directly into the landscape using a spacing of 12 to 18 inches
(30.5 to 45.7 cm) and planted to a depth where plant crowns are
visible after watering. They require about 7 to 10 weeks of grow-
ing time before they bloom.
Plants purchased in compartmentalized containers should be
transplanted as soon as possible, preferably the same day of pur-
chase. Flower beds should be prepared before plants are pur-
chased. Plants grown in small compartmentalized trays usually
have pot bound root systems. If planted without disturbing, the
root system will be slow to establish with the surrounding soil








and plants will suffer from lack of moisture if not watered daily. A
preferred method is to loosen and untangle the root system
without breaking the soil ball. Plants will usually recover rapidly
and become established quickly.
Excessive moisture during the rainy season may increase the
incidence of root disease. Growing gerberas in raised beds or
mounds allows excess moisture to drain rapidly to alleviate or
reduce this problem.
Mulching with organic material to conserve some moisture and
reduce solar heating of soil is beneficial. Black plastic mulches
should never be used, except when a layer of organic mulch is
added on top of the black plastic.
Gerbera crowns gradually sink into the soil after a period of
growth. The crown becomes entirely submerged after a year or
two and excess moisture at this time tends to induce crown rot
organism infestation causing crowns to gradually weaken and
die. Plants should be dug after two years and replanted to keep
crown rot under control.
Gerberas respond to high fertility levels and should be fertilized
on a regular basis. A complete fertilizer (6-6-6, 8-8-8, etc.) should
be applied at a rate of 3 pounds per 100 square feet (1.5 kg/10m2)
of bed area every month during the growing season (March-
October for north Florida and February-November for central and
south Florida). Gerberas respond best to controlled release or
organic fertilizers which slowly release nitrogen over a long
period of time.
Gerberas grown in Florida's sandy soils often express deficiency
symptoms for the microelements iron and manganese. A
microelement fertilizer should be incorporated into the soil prior
to planting. If deficiency symptoms appear after plants have been
grown for a period of time, spray with a liquid microelement for-
mulation to correct the problem.
Gerberas are full sun plants, but they also will thrive under
30-50% shade. Spent blooms and old leaves should be removed
promptly to avoid possibilities of disease infestations. Dead
tissue usually serves as entry points for disease.
Large specimen plants are available at some garden supply
stores and nurseries. They are more expensive plants that have
usually been propagated vegetatively by tissue culture and grown
to maturity. Most are sold in 51/2 to 6 inch plastic pots and are in
bloom when purchased making desired color and flower type
selections easy. Rather than waiting for smaller seedlings to pro-
duce flowers of unknown color and form, these plants provide in-
stant color in flower beds. Specimen plants do not have to be








transplanted right away and can be grown in pots, placed under
partial shade and watered when needed. Plants left in pots
should be fertilized weekly with a water soluble fertilizer such as
20-20-20 at a rate of 1 tablespoon per 2 gallons (15 mi/L) of water
until they are ready to transplant into beds. These plants can also
be transplanted into 3 gallon pots and placed on patios, decks,
around swimming pools, or along driveways.




Seed
The most inexpensive way to produce gerberas is from seed
obtained from reputable seed companies throughout the United
States. However, plants propagated from seed are usually not
true to type and may vary greatly in flower color.
Seed should be germinated in an artificial growing medium.
Germinating seed in field sand or field sand mixed with materials
such as perlite and/or peat moss is not recommended since it is
usually not sterile, contains weed seed and may be infested with
nematodes, insects and fungi. Artificial growing media which are
sterile, lightweight, and have good water retention capacity and
drainage can be purchased in garden supply stores. These
materials often have fertilizers incorporated.
The medium can be placed in flats or pots which have drainage
holes. Make shallow rows in the medium approximately twice the
depth of the diameter of the seed, sow seeds in the rows, cover
lightly with extra medium and water carefully.
Artificial mixes containing peat moss are difficult to wet when
dry, thus they should be watered thoroughly prior to planting
seed. After seeds are planted and watered, cover the container
with a sheet of glass or clear plastic and place the germination
container approximately 18 inches (45.7 cm) below a fluorescent
light. Check the medium daily for moisture and for signs of seed
germination. The medium should never be allowed to dry,
especially when seeds are starting to germinate. When watering
is necessary apply a sufficient amount to allow excess water to
drain out of the container. Any water that collects in the saucer
beneath the germination container should be discarded. Allow-
ing germinating seeds to remain in excess water will damage the
root system. Tall and spindly seedlings can be avoided by
transplanting seedlings to small pots as soon as the first true
leaves appear. Seedlings can be grown in small pots until they
are large enough to transplant into flower beds.








Division
Desired cultivars can be obtained by dividing parent plants
(Fig. 2). One year old plants consisting of multiple plants (crowns)
can be dug and divided any time of year in south Florida and dur-
ing spring and summer in north Florida. Plants should be lifted,
cleaned, and each crown separated with a clean sharp knife or
pruning shears. Dead roots and old decaying leaves should be
removed. Plants can be soaked in a solution of 1 part liquid
bleach and 10 parts water for 10 minutes to avoid spreading
diseases. Extending the soak time could damage or kill the plant.
Remove one-half of all mature leaves by cutting crosswise ap-
proximately halfway between the petiole and distal end of the
leaf blade. Plants should be replanted immediately and kept
moist to minimize excessive wilting.

Pests and Diseases
Gerberas have insect and disease problems and to successfully
grow specimen plants these problems must be recognized and
control measures initiated.
Insects that attack gerberas also are common to many other
plants. The most destructive are leaf miners which are tiny flies


Figure 2-A. Dig plants and remove soil from roots.


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Division
Desired cultivars can be obtained by dividing parent plants
(Fig. 2). One year old plants consisting of multiple plants (crowns)
can be dug and divided any time of year in south Florida and dur-
ing spring and summer in north Florida. Plants should be lifted,
cleaned, and each crown separated with a clean sharp knife or
pruning shears. Dead roots and old decaying leaves should be
removed. Plants can be soaked in a solution of 1 part liquid
bleach and 10 parts water for 10 minutes to avoid spreading
diseases. Extending the soak time could damage or kill the plant.
Remove one-half of all mature leaves by cutting crosswise ap-
proximately halfway between the petiole and distal end of the
leaf blade. Plants should be replanted immediately and kept
moist to minimize excessive wilting.

Pests and Diseases
Gerberas have insect and disease problems and to successfully
grow specimen plants these problems must be recognized and
control measures initiated.
Insects that attack gerberas also are common to many other
plants. The most destructive are leaf miners which are tiny flies


Figure 2-A. Dig plants and remove soil from roots.


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Figure 2-B. Separate the parent plant into individual plants.


Figure 2-C. Remove dead roots and leaves and soak plants in a solution of 1 part
liquid bleach and 10 parts water for 10 minutes.








r


Figure 2-D. Remove one-half of all mature leaves.


Figure 2-E. Plants should be replanted and watered immediately.









that deposit eggs on the leaves. Resulting larvae bore tunnels be-
tween epidermal layers of leaves. These tiny larvae feed as they
bore tunnels and produce white streaks on leaves. Heavy leaf miner
infestation can cause a collapse of cells and eventual death of parts
of leaves which gradually turn brown. These areas become an ideal
place for secondary fungal organisms to become established. There
is little than can be done when larvae are feeding since they are
protected from most insecticide spray by the leaf epidermal layer.
Periodic pesticide application may minimize additional infestation.
Caterpillars, leaf chewing worms, and cutworms can also be
destructive. Plants attacked by caterpillars have ragged leaves
which may suddenly wilt and turn brown when young leaf
petioles are damaged.
Thrips and red spider can also be a problem. These are minute
insects that rasp and suck juices from plant cells. They often go
undetected because they usually feed on the underside of leaves.
Infestations are most severe when plants are subjected to pro-
longed water stress during hot dry weather.
A number of fungal organisms affect gerberas. Some of the
more important ones are gray mold and powdery mildew. Gray
mold is caused by the fungus Botrytis cinerea which attacks
dead plant parts and when conditions are favorable, the organism
feeds on living leaf and flower tissue. Sources of infestation can
be avoided by removing dead or spent flowers and dead or dying
leaves promptly.
Powdery mildew is a problem usually occurring when plants
are subjected to prolonged wet, humid weather. Powdery mildew
requires moisture before it can become established. If leaves re-
main dry and sufficient air movement is present, it will not
become a problem. Specific insect and disease control recom-
mendations can be obtained from your local County Extension
Office.

This publication was promulgated at a cost of $1,010, or .106 cents per
copy, to inform interested residents about growing gerberas in Florida.
4-9.5M-82.

COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLOR-
IDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES,
K. R. Tefertlller, director, in cooperation with the United States
Department of Agriculture, publishes this information to further the
purpose of the May 8 and June 30, 1914 Acts of Congress; and is
authorized to provide research, educational information and other
services only to individuals and institutions that function without regard to race, color,
sex or national origin. Single copies of Extension publications (excluding 4-H and Youth
publications) are available free to Florida residents from County Extension Offices.
Information on bulk rates or copies for out-of-state purchasers is available from C. M.
Hinton, Publications Distribution Center, IFAS Building 664, University of Florida,
Gainesville, Florida 32611. Before publicizing this publication, editors should contact
this address to determine availability.