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Group Title: Circular - University of Florida Institute of Food and Agricultural Sciences ; 465
Title: Gesneriads for the Florida gardener
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00067085/00001
 Material Information
Title: Gesneriads for the Florida gardener
Series Title: Circular
Physical Description: 10 p. : ill. ; 23 cm.
Language: English
Creator: Bodnaruk, William H
Tija, B
Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1979?
 Subjects
Subject: Gesneriaceae   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: William H. Bodnaruk and B. Tija.
Funding: Circular (Florida Cooperative Extension Service) ;
 Record Information
Bibliographic ID: UF00067085
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 19639732

Table of Contents
    Historic note
        Unnumbered ( 1 )
    Front Cover
        Page 1
        Page 2
    Main
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Back Cover
        Page 12
Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida












Circular 465
4z
AV








SGesneriads
a for the
Florida Gardener
Wi ia', H. Bodnaruk and B. Tija


AP 6 1980








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
















Gesneriads

for the

Florida Gardener


William H. Bodnaruk and B. Tjia*



Florida's plant enthusiasts should become well acquainted with the Gesneriaceae,
a family which includes some of the most popular hanging basket and flowering pot
plants. Virtually all gardeners are familiar with two gesneriads, African violets and
gloxinias, but few are aware of the many other species and hybrids which make ex-
cellent flowering pot or hanging basket plants and dish garden and terrarium sub-
jects. The appeal of gesneriads lies not only in their abundant, colorful flowers, but
also in their attractive and colorful foliage, desirable growth characteristics, and
relative ease of culture and propagation. As a group, gesneriads are long-lived,
robust plants which flower profusely under Florida's climatic conditions. By ob-
taining healthy, vigorous plants from retail outlets or specialty nurseries and fol-
lowing the suggestions outlined below, Florida's gardeners should be successful at
growing gesneriads.

Choosing Gesneriads
A good way to choose a gesneriad is to first determine how the plant is to be
grown, whether as a hanging basket, a pot plant, or as a terrarium or dish garden
subject; then select a gesneriad which is suited for the particular effect.
Listed below are some widely grown and readily available gesneriads and sugges-
tions for their use:

*Extension Agent, Lake County, FL; and Assistant Professor, Extension Floriculture Specialist,
Department of Ornamental Horticulture, Institute of Food and Agricultural Sciences, University
of Florida, Gainesville; respectively.

The use of trade names in this publication is solely for the purpose of providing specific infor-
mation. It is not a guarantee, warranty, or endorsement of the products named and does not
signify that they are approved to the exclusion of others.









Achimenes x x
(Magic Flower)
Aeschynanthus x x*
(Lipstick Plant)
Codonanthe x x
Columnea x x*
Episcia x x* x
(Flame Violet)
Gesneria x x
Nematanthus x x*
(Goldfish Plant)
Saintpaulia x x
(African Violet)
Sinningia speciosa x
(Gloxinia)
Sinningia x x
(miniatures)
Streptocarpus x** x
*Best grown as hanging baskets but will make fine pot plants if well maintained.
**Pendant types make good hanging basket material, and upright varieties are prime pot plants.


Achimenes (Magic Flower) are popular hanging basket and pot specimens pro-
ducing large (1-2 inches in diameter) colorful flowers during summer. Flower colors
include red, pink, yellow, lavender, violet, and blue, ranging from intense hues to
pastels. Varieties with white flowers, white with colored venation or colored with
white throat are very attractive.
Aeschynanthus species and hybrids (Lipstick Plants) are ornamental trailing
plants best grown in hanging baskets. Brilliant red, orange, yellow and combina-
tions of these are found in tubular flowers produced in abundance in spring and
summer. The emerging red flower buds and tubular calyx of A. radicans and A.
pulcher resemble a lipstick, hence the common name, Lipstick Plant. Aeschynan-
thus marmoratus, with maroon venation marking glossy green leaves, makes attrac-
tive foliage in hanging baskets.
Codonanthe and Nematanthus have excellent potential as hanging basket speci-
mens in Florida. In Codonanthe, tubular white flowers project outward from suc-
culent glossy green leaves suspended below the hanging container. Orange, pink or
white marble-sized berries follow the flowers, prolonging the show of color. Nema-
tanthus varieties are trailing or semierect plants noted for their brightly colored,
pouch-shaped flowers and free flowering habit.

Columneas produce some of the most magnificent flowering hanging baskets in
the Gesneriaceae family. Columneas are trailing or semi-erect plants with brilliant
yellow, orange, red, pink or combination colored tubular flowers several inches in


Genus


Hanging Basket Pot Plant


Dish Garden/Terrarium







length and up to one inch across. Flowers develop year round in the axils of leaves
and project away from the foliage.
Episcias are favorite hanging basket and terrarium plants valued especially for
their attractive, often multicolored foliage and colorful funnel-form flowers. Leaves
may be of silver, bronze, emerald green or steel blue over brown or they may be
decoratively veined in contrasting brown, green, silver or rose. Flowers are produced
in a variety of shades from pink and red to lavender from early spring to late fall.
Gesneria and miniature sinningias (miniature gloxinias) are ideal subjects for dish
gardens, terrariums, and dwarf flowering pot plants. Gesnerias are low growing (less
than 6 inches), evergreen plants decorated year round with brightly colored tubular
flowers borne on tiny peduncles. Miniature sinningias rarely exceed 3 inches in
height but produce abundant large flowers (2 inches in length) continuously
throughout the year.
Saintpaulia ionantha
Saintpaulia ionantha (African violets), Sinningia speciosa (Florist's gloxinia) and
stemless Streptocarpus Rexii hybrids are the best known gesneriads in the trade,
each being in cultivation for more than 50 years. As a result of hybridization within
each group, a wide variety of flower colors can be obtained. Single, double, and
multi-flowered varieties of African violet and gloxinia are available. African violets
with ruffled and variegated foliage are common and all are everblooming. Strepto-
carpus hybrids are also everblooming while gloxinias tend to be more seasonal,
flowering after three months of rest.
Pendant varieties of Streptocarpus are excellent hanging basket subjects produc-
ing funnel-form lavender flowers on wiry pedicels throughout the year.

Dormancy in Gesneriads

Most temperate flowering plants respond to adverse environmental conditions,
i.e. cold, by losing leaves and becoming dormant. Certain tropical species face
equally adverse conditions, mainly those imposed by drought and also respond by
entering dormancy. In the gesneriad family, sinningias and Achimenes naturally go
dormant despite continued favorable growing conditions under cultivation. Seeing a
prize gloxinia or magnificent Achimenes decline and die after months of lush
growth and flowering is often more than a novice grower can bear, and the "prize"
plant is subsequently discarded in a fit of anguish.
Do not despair, however, as these plants are perennials (flower over many years)
and reemerge from dormancy with vigor following a rest period. After the flowering
season, foliage declines and gradually yellows or "dies back." The surviving under-
ground storage organs, tubers in gloxinias or catkin-like rhizomes in Achimenes,
should be kept dry. For the next 2-3 months, water the barren pot monthly to pre-
vent tubers or rhizomes from dehydrating. This is the best time to repot or to
separate Achimenes rhizomes or slice gloxinia tubers for propagation. Small, pubes-
cent "rabbit ears" just breaking the soil surface signal and end to the rest period
and resumption of active growth. At this time, begin to gradually increase watering
frequency and fertilization to normal levels.







Propagation

Most gesneriads are commonly propagated from stem cuttings and seed. Sprinkle
seed over moist soil in a pot and cover with glass or a plastic bag to prevent drying.
Transplant seedlings to individual pots when 1-2 inches tall. Seedlings flower with-
in 5-7 months depending on species. Stem tip or mid-section cuttings of most
species are easily rooted in a pot of moist soil or vermiculite/perlite mixture. Water
frequently, to maintain soil moisture and high humidity around the cuttings. Keep
the rooting medium moist, but not soggy.
African violets, gloxinias, episcias and Streptocarpus are propagated easily by
leaf cuttings. Detach mature, healthy, green leaves with part of petiole, if present,
from the parent plant and cut notches across major veins on the undersides of the
leaves. Place the leaves on the soil mix, undersides touching the mix, bury the cut
end of the petiole, and weight the leaves down to prevent curling.-Plantlets will
develop from the cut surfaces within several months. African violet growers prefer
to stand the leaves vertically or slightly sloped to a 450 angle with 1 inch of petiole
planted in the propagation medium. Plantlets then develop below the soil line
from the petiole.
African violets and Streptocarpus tend to form clumps when propagated from
leaf or petiole tissue. Specialists prefer to grow single stemmed plants and use off-
sets as propagating or trading stock. Break the offset shoot from the parent plant
and then pot it in the standard potting mixes.
Achimenes may be propagated during its dormant season by digging and separat-
ing rhizomes or by breaking individual rhizomes into V inch pieces prior to re-
potting. When repotting, bury rhizomes about 1 inch deep.



Media and Containers

A medium for gesneriads should be light, well drained, and porous yet have a
high water holding capacity. Commercial growers and researchers agree that
"soilless" mixes composed of peat and sand, vermiculite, or perlite are best suited
for growing gesneriads. A popular mix consists of 50% peat and 50% perlite or
vermiculite amended with 2 tablespoons of dolomitic limestone for each quart of
prepared mix. Better still, artificial mixes suitable for gesneriads are available in
many retail nursery stores. Since best growth is obtained when the mix is light and
porous, avoid pressing the medium around the roots but gently tap the pot to
settle the mix.
All types of plant containers may be used for gesneriads, with just one stipula-
tion: drainage must be provided. Plastic, clay, and glazed pots are commonly used
for pot plants. Plastic, wire, and redwood containers find use as hanging baskets.
Dish garden and terrarium enthusiasts use all kinds of containers from thimbles for
Sinningia pusilla (smallest of the miniatures) to teacups, brandy glasses, and aquari-
ums for larger specimens.







Watering and Fertilization Practices


Keep actively growing gesneriads moist at all times. Lack of moisture wilts
flowers, reduces their lasting quality, and in Achimenes and Sinningia leads to pre-
mature dormancy of plants. When watering, saturate each pot thoroughly so that
moisture drains from the bottom of the pot. Overhead watering is satisfactory for
all gesneriads and does not contribute to leaf spotting unless the water temperature
is 10F (5.50 C) or more degrees warmer or colder than the leaf temperature. A
good rule to follow to avoid cold water damage is to keep a container of water in
the room or greenhouse where plants are grown so that water and plants are the
same temperature. African violet growers use self-watering techniques, where water
is drawn into the soil through a mat, by capillary action from a reservoir below the
pot.
A complete fertilizer with a 1-1-1 ratio is recommended for gesneriads. These
fertilizers are available in soluble, dry, or slow release formulations. Fertilizers with
the same basic ratio may be interchanged but be sure to adjust for changes in con-
centration. For instance, a recommendation may be given in terms of 20-20-20, i.e.
/2 tablespoon/gallon, but a 10-10-10 fertilizer may be all that is available. Use the
10-10-10 but keep in mind that this material is half as concentrated as 20-20-20;
therefore, compensate by using 1 tablespoon/gallon.
Slow release type fertilizers such as Osmocote, ProGro, MagAmp, etc.* release
nutrients slowly over a period of 2-3 months. One application of Osmocote
14-14-14 at the rate of 1 teaspoon/6 inch pot is sufficient for 2-3 months, and
plants will be continuously fertilized. Soluble fertilizers are dissolved in water and
applied in place of a normal watering. Mix tablespoon/gallon of 20-20-20 and
apply monthly. Dry materials such as 20-20-20 garden fertilizer can also be used for
gesneriads at rates of /2 teaspoon/6 inch pot applied monthly.
Over fertilization, "salty" irrigation water, and poor watering practices contri-
bute to high soluble salt levels in the soil, which cause root damage and subsequent
yellowing of leaves. A good habit is to leach thoroughly each time plants are
watered to prevent fertilizer and salt build-up in the growing medium.

Light and Temperature
Gesneriads require partial shade for optimum growth and flowering. Achimenes,
Aeschynanthus, Codonanthe, Columnea, Nematanthus, and Sinningia thrive at light
levels between 2000-2500 fc (20-25K lux). Episcia Saintpaulia and Streptocarpus
grow best at 1000 fc (10K lux). These shade levels may be obtained by growing
plants under saran cloth or trees, shading the greenhouse with whitewash, or by
utilizing shady corners in and around the house. Gesneria, miniature sinningias,
episcias, African violets, and Streptocarpus grown indoors will flower with as little
as 750 fc (7.5K lux). Position pots, dish gardens, and terrariums near southeast,

*The use of trade names in this publication is solely for the purpose of providing specific infor-
mation. It is not a guarantee, warranty, or endorsement of the products named and does not
signify that they are approved to the exclusion of others.







south, or southwest facing windows and filter direct sunlight through sheer curtains
if possible.
Tropical gesneriads need to be protected from cold temperatures. All species dis-
cussed earlier will stop growing when temperatures are between 50-550F (10-13C).
Gesneriads are tropical plants and will be damaged when subjected to temperatures
of 50F (100C) or below for a period of 6 hours. Plants will continue to grow and
flower if night temperatures are maintained within a range of 65-750F (18-24C).

Insects and Diseases

Florida gardeners need to be aware that gesneriads are susceptible to a number
of diseases and insect pests. Generally, problems of this nature may be minimized
by practicing the cultural and sanitary techniques described below.
1. Use pre-sterilized soil components or artificial mixes sold by garden centers.
Bagged peat, vermiculite, and perlite are usually sterile, but sand may not
be.
2. Space plants to increase air circulation, reducing the potential for disease.
3. Water early in the day so leaves and crown are dry by late afternoon; better
still, avoid wetting foliage when watering.
4. Remove weeds as these may harbor insects and diseases.
5. Remove yellow, dead, and decaying plant parts.
6. Allow water to drain from pots each time plants are watered.
Despite conscientious efforts to prevent pest problems, occasionally they arise
and some pesticide treatment may be necessary. Consult your local county agri-
cultural Extension agent for the latest pesticide recommendations.
Common insect pests that Florida's gesneriad growers may face are:
1. Mealybugs, small, white, cotton-like animals infesting axils and undersides
of leaves. These insects are very bothersome but are easily controlled on a
few plants by squashing individuals with cotton swabs. Root mealybugs
reside in the soil and feed on roots, causing the plant to slowly deteriorate.
If root mealybug is suspected, knock plants from pots and look for cottony
masses in the medium.
2. Mites, particularly microscopic Cyclamen mites. These insect pests infest
and feed in tiny bud leaves and flowers, distorting their shape or if severe
causing abscission. During warm and dry weather, mite populations flourish.
Therefore, keep watch for mite damage and treat with miticides if neces-
sary. Misting plants frequently during hot weather helps reduce mite infesta-
tions.
3. Aphids and caterpillars. These insect pests are sometimes encountered.
Aphids, or plant lice, are soft-bodied yellow, green, pink or black insects
which damage new growth by sucking plant juices. Caterpillars devour
chunks of leaf tissue, rendering the plant unsightly.

Gesneriads are subject to several diseases, but their occurrence can be minimized
if the guidelines presented earlier are followed. However, be on the lookout for:








1. Root and crown rot-roots, stems, and leaves become limp, soggy, dark
brown, and water soaked. Nothing can be done to save plants once infected,
so discard it immediately and propagate from healthy stock. Be sure to use
sterile propagating and potting mixes.
2. Bud rot (Botrytis)-humid crowded conditions and wet leaves are conducive
to development of a gray mold infecting leaves, buds and flowers. To reduce
the occurrence of Botrytis, space plants to provide adequate air circulation
and remove dead flowers promptly. Avoid wetting flowers and foliage when
watering.

Ways to Propagate a Florist or Holiday Gloxinia: *

After bloom, remove all spent flowerstalks and grow the plant for 1 to 2
months. Gradually reduce water until foliage turns yellow and dies. Remove with-
ered and dead foliage, withhold water, and store in a dry area. After 2-4 months
the bulb will generate new shoots. When shoots become visible (commonly called
rabbit ears), dig bulb and cut into 2 or more pieces and plant the pieces into indivi-
dual pots (la). Apply small amount of fertilizer and water. If only one multiple
crown plant is desired, leave bulb in original pot, apply fertilizer, and water (1b).
A large number of plants can be obtained from seeds of one plant. After flowers
are spent, remove flowers but allow flower stalks to remain. Flower stalks that do
not contain viable seed usually wither and these should be removed. When seed
pods begin to open, remove entire seed stalks and collect seed by gently tapping
stalks over a piece of white paper or sprinkle seed directly on a commercial germ-
ination medium. Without covering the seed, soak the container in water until the
medium is moist. Cover container with a piece of glass or plastic and place near a
window receiving indirect sunlight. When seedlings are large enough to handle,
transplant them into individual containers.
Cut leaves from plant after bloom and place them on a growing medium such as
sterilized sand. Cover parts of the leaves with growing medium to hold the leaf
margins in close contact with the medium. Cut or injure leaf margins with a clean
sharp knife to initiate the formation of small plants along the margins of leaves.
Keep medium moist and cover container with clear glass or plastic. To prevent rot-
ting of leaves and establishment of disease organisms, do not allow the glass or
plastic to touch leaves where there will be water condensate. This prevents condes-
sate from dripping on leaves. When a clump of small plants have developed suffi-
ciently to handle, remove them from the leaf. Multiple plants can be planted when
a multiple crown plant is desired (3b) or separated to obtain single crown speci-
mens (3a).
Cut leaves from plant leaving 1/2 inch of each leaf stem (petiole). Place the
petiole into a moist sand medium about /2 to 1 inch deep. Roots will appear at the
base of the petiole in 3 to 4 weeks under good growing conditions. In 6 to 8 weeks,
leaves of new little plants will appear at the surface of medium. Separate and pot
each plant individually, if single-crown plants are desired (4b); do not separate for
multiple crown plants (4a). Discard the original leaf cutting.
*For illustration of ways to propagate a gloxinia, see Figure 1.











a

b


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dA^A^ 3 -"':" fa


b



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Figure 1-- Ways to Propagate a Florist or Holiday Gloxinia.


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10-5M-79



This public document was printed at a cost of
$445, or 9.0 cents per copy, to provide informa-
tion about Gesneriads for the Florida Gardener.





Single copies are free to residents of Florida and may be ob-
tained from the County Extension Office. Bulk rates are
available upon request. Please submit details of the request to
C. M. Hinton, Publication Distribution Center, IFAS Building
664, University of Florida, Galnesville, Florida 32611.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service. IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


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