Title: Caladium production in Florida
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00084480/00001
 Material Information
Title: Caladium production in Florida
Series Title: Caladium production in Florida
Alternate Title: Circular 128 ; Florida Agricultural Extension Service
Physical Description: Book
Language: English
Creator: Sheehan, Thomas J.
Publisher: Agricultural Extension Service, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: February 1955
 Record Information
Bibliographic ID: UF00084480
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 226063145

Full Text


Circular 128 Febru1ary 1955



in Florida

SI ssistawnt O rnamental HortictIturist

Although caladiums have been grown in Florida for many
years, it was not until 1940 that the industry began to expand.
It is estimated that there are now over 300 acres devoted to
caladium tuber production. IIi1lri:iid- County is the center of
the industry, with between 200 and 250 acres devoted to com-
mercial production. Sebring is generally recognized as the
caladium capital of the United States and possibly of the world.
The annual production in the area is between 15 and 20 million
iu1li-rt,. with another 2 to 4 million produced elsewhere in the
As early as 1910 Dr. Henry Nehrling in Orlando was noted
for his collection of fancy leafed caladiums. It has been stated
that he had 2,000 named varieties and shipped 100,000 to
150,000 tubers each year. .\[any of these varieties were Dr.
Nehrling's own hybrids, from crosses he made as early as
Caladiums are members of the Aruceac family and are Tropi-
cal American in origin, with a large portion of them coming
from the Amazon basin in Brazil. Caladium bicolor is the
usual species in cultivation and is the species which has given
rise to many of the named forms cultivated today. C. pictura-
turn, native to Brazil and Peru, is also cultivated to some extent.
These two species are the parents of most of our named hybrids
in the trade.
Most of the tubers produced are used for fl.i ing under glass
in the early spring months. They make ideal pot plant subjects
for Easter, Mother's Day and spring and summer sales. A small
percentage are pi;m'kaLC;g- and sold in retail and chain stores for
home use.
SFancy Tnafere Caladiumns, K{oberl Mi'echell. Ohio Florkists Bulltin No. 228, Sept., 19418.

The number of varieties grown varies with different growers.
The larg!t producers will have up to 50 varieties under culti-
vation at one time, whereas some small growers will cultivate
only two or three varieties.
The majority of the tubers produced in Florida are grown in
open fields in moist muck pockets. These areas are acid, hav-
ing a pH near 4.5, which seems to be ideally suited for their
growth. Some are being grown
on sandy soils and as long as
these are irrigated and ;inii
S sufficient fertilizer they will
-- produce good tubers.
Propagation. Caladiums
/ can be grown from seed, but
when a new variety is selected
it is propagated vegetatively.
The plants produce tubers dur-
Fig. 1.-Caladium tuber. ing the griwi season and
these become the ir.i;ig; t ing
stock for the following year. The tuber will have several eyes
or buds on the top and sides. It can be cut into as many pieces
as there are eyes (Figs. 1 and 2) and each piece will produce a
new plant. The general prac-
tice, however, is to leave at
least two eyes on each piece.
Planting.-There is consid-
erable variation among grow-
ers when it comes to planting w
and .ia,;ing the chips (i.e. a
small piece of a tuber, con-
taining the eyes, that is used Fig. 2--Caladium tuber sectioned
into "chips" for planting.
for planting stock). The av-
erage producer prel-p;i.-, his fields in late February and begins
planting in March and continues until all the chips have been
set. Some growers will still be plainling in June. The main
reason for this long planting season is the soft nature of the
caladium tuber. The soft tuber has not lent itself to mechanical
digging and il1,an ing equipment, hence all this type of work must
be done by hand. The rows are spaced 18 to 24 inches apart
and the chips are planted from 4 to 6 inches apart in the rows,
and 3 to 4 inches deep. The spliacinu between the rows will de-

pend entirely upon the type of equipment used in cultivating
the fields. Some growers plant up to 80,000 chips per acre.
Care in the Field.-When the field is prepared in the spring,
fertilizer is applied at the rates of 500 to 800 pounds of 8-8-8
or 4-8-8 per acre. This initial application is followed after plant-
ing by two or three sidedressings of 500 pounds of 8-8-8, 4-8-8
or 3-10-12 per acre, :ii,1ii-.1 during the growing season. In gen-
eral, most growers will decrease the amount of nitrogen applied
and increase the amount of potash so that their last application
will be 3-10-12 or a similar formula. The additional potash will
mature and harden the tuber and thus increase its storage po-
Weeding is one of the biggest problems of the caladium indus-
try. The major portion of the growers are still hand weeding,
while a few have tried using various herbicidal treatments to
control weeds. The latter group are finding some materials
very effective in keeping the weeds under control. However,
since all effective weed killers have caused severe leaf burn, ex-
treme care must be used in .,ill.1v ig the material. Shielding the
nozzles has all but eliminated leaf burn. One application of
weed killer is effective for six to seven weeks and eliminates
three or more hand v .-iling or cultivating operations.
Roguing is a problem on fields that have been in caladium
production for several years. In digging, chips are left in the
soil and after mild winters they will produce plants the following
season. These rogues are pulled either during weeding opera-
tions or just before harvest time, when they are all removed in
one operation.
Harvesting.-Caladiums stop growing with the first frost
and are usually harvested at that time. Growers begin digginglr
in November and continue until all the tubers are harvested.
Here, too, there is a great deal of variation in that some growers
prefer to harvest all the tubers at once, while others dig as they
fill orders. The latter group will still be digLingg in February,
when it is time to plant again. They will sometimes run into
heavier losses if there is an extremely cold winter, at which
time the tubers left in the ground may be injured by the cold.
Once the tubers are harvested they must be cured or dried.
[.Mi.- are dried in open sheds or sheds with forced air drafts.
A few growers are using modified hay dryers. Although these
have cut the time of curing considerably, the cost of the equip-
ment has prevented most growers from aIdiltiipi them. The

harvested tubers are placed in trays with slatted or wire bot-
toms, with the tubers one l],vlte deep. The trays are then stacked
in the di',ilig shed where they are air dried for six weeks or
mechanically dried for at least 48 hours. After the initial drying
period the tubers are stored three to five layers deep in trays to
hold for shipping or for storage for next year's plantings. The
temperature in (dt.'inv and storage should not go below 600 F.
The tubers are graded before shipment. They have four classi-
li'natinii.-, but only the three larger grades are customarily offered
for sale. The following are the grades used:

Mammoth-3 "/, or larger in diameter
Jumbo --2 3 "
No. 1 --11 2"2"
No. 2 -1 11
The percentage of each grade produced varies from year to
year. The average production of caladium tubers runs 15%
mammoth, 25'% jumbo, 25% No. 1, 20% No. 2 and an average of
15% loss due to disease and other problems. These figures will
vary also by variety. Some types will seldom produce a tuber
larger than a number 1, while other varieties will produce a
larger percentage of jumbos and mammoths. The largest part
of the number 2 production goes into planting stock for the fol-
lowing year. Some are sold in small packages for home owner
use and a few are used as forcing stock for small pot material.
Insects and Diseases.-Insects are generally not too trouble-
some in caladium production. Occasionally aphids and thrips
can become a problem. Larger growers keep both of these
under control by spraying with parathion or malathion. Smaller
growers and home owners use DDT spray or dust for thrips
and nicotine sprays or dust for aphid control. Cutworms have
made minor attacks but have never become a serious pest.
Nematodes are a problem in caladium culture. Soil steriliza-
tion of small plots has been very satisfactory in controlling
nematodes. The larger acreages do not lend themselves too
well to soil sterilization, although fumigation with materials
such as EDB can be used. When an infestation builds up the
grower usually rotates his crop by planting on new land and
putting cover crops on his old land.
Southern blight (Sclerotium rolfsii) is a problem in some cala-
dium fields. This disease is soil-borne and can wipe out the
plants in very short order. Soil sterilization will help control
it, but in field culture it is difficult to control. All diseased

plants should be discarded and a good rotation program should
be set up. As with nematodes, Southern blight is most preva-
lent on fields that have been used for caladiums year after year.
Tuber rot also is common. It occurs when the tubers are
stored or held at temperatures below 500 F. for brief periods.
Chalking, or dry white rot of tubers, is another problem.
The cause of this malady is unknown. It occurs frequently in
storage, yet does not seem to be too deterimental to forcing
Foliar burns occur from time to time in the field and in the
greenhouse. These have been attributed chiefly to lack of water
or water damage to the root system, rather than to any disease.
Forcing Caladiums.-Tubers for forcing can be obtained from
mid-December on. Most tubers used in forcing are planted from
January to May. There is little known regarding the dormancy
requirements of the tubers, but it has been noted that tubers
planted in January do not grow as rapidly as those planted in May.
January forcing usually take six to eight weeks to produce a
salable plant, whereas those forced in May require only four
to six weeks. Growers forcing early will select varieties that
have their color marking on the juvenile leaves, leaving for late
spring forcing those varieties that show color only on the adult
leaves. Actually caladiums can be taken up at any time and
dried for two to three weeks and then forced again. Frequently,
an early crop that does not meet a favorable market can be
dried and forced for a later season.
Caladiums can be started in flats containing a mixture of 2
parts wet peat moss and 1 part sand, or they can be started
directly in the pots in which they will be sold. A minimum
temperature of 700 F. is required for forcing, with temperatures
between 80" and 900 F. being considered ideal. The tubers
should be placed in the flats so that they are barely covered with
the rooting medium. After the roots are 2 to 3 inches long the
tuber can be removed from the flat and planted in the pot in
which they are to be sold. The pot should contain a soil com-
posed of 1, sandy soil and 1/ organic matter. One teaspoon of
complete fertilizer (6-6-6) per 5-inch pot will promote good
growth. Once growth begins the plants require large quantities
of water, and should be kept uniformly moist. Once the tubers
have been potted they are grown at a minimum night tempera-
ture of 650 F. Although the tubers are produced in the field un-
der full sun, most growers force them in partial shade with a
maximum light intensity of 5,000 foot candles. This lowered

light intensity will frequently produce a different color pattern
on the foliage from that obtained under field conditions.
When forcing tubers the
1 central eye will break first,
S-% producing a few leaves in a
large spot, with a few small
shoots developing later. The
/ best way to avoid this is to
/ / section the tuber before pot-
ting. If the tuber is cut into
three or four pieces and these
pieces placed "back-to-back"
they will produce more shoots
Fig. 3.-Caladium tuber with central and leaves of unior size,
eye removed for forcing. and leaves of uniform size,
which in turn will make a
fuller pot for future sales. Others prefer to cut out the central
eye and thus force the lateral eye without cutting the tuber
(Figs. 3 and 4).
Varieties.-There are numerous varieties and named hybrids
on the market today. The demand for the different colors varies
considerably with locality and season of the year. The nom-
enclature of varieties is very
confusing in that some varie-
ties are being sold under more
than one common name by dif-
ferent growers. The following
list of varieties and their brief
descriptions are those that are
the most popular today.
Candidum-snow-white leaf
with green netted veins, border I 4.-Cal aium er quartered
narrow and green. Most popu-
lar white and green variety. Popular Easter variety.
Lord Derby-pink or rose-red leaf, almost transparent, edges
and ribs deep green. (Hortulanus is similar.)
Ace of Hearts-deep rose center, borders of leaf green, ribs
scarlet and heavy.
Crimson Wave-crimson crinkled centers, large leaves deep
green, almost transparent, some crimson spots in the wide green
John Peed-metallic red center, with dark green border.
(Freda Hemple is similar.)

Porcile Anglais-metallic green edged, waxy leaves, centers
a deep crimson, a low-growing variety.
Red Ensign-metallic red, narrow green border, very bright
coloration, medium height.
Scarlet Pimpernelle-scarlet leaves, margin yellow or straw
colored, leaves large.
Spangled Banner-red glowing leaves, ribs darker red, numer-
ous pink spots. (John Hortmiester is similar.)
Thomas Tomlinson-bright crimson center, crimson blotches
in green border, produces large numbers of leaves.
Some additional named varieties in the trade include:

Mrs. Arno H. Nehrling
Mrs. F. Sander
Mrs. W. B. Haldeman
Pink Cloud
Tuoinphe de 1' Exposition
Miss Chicago
Red Flare
Dr. M. Cook
Edith Mead
Fire Nymph
Jessie Thayer

Marie Moir
Texas Wonder
Vivian Lee
Red Glory
Red Poker
Red Skin
Richard Deckard
Rising Sun
Scotch Plaid
Sea Gull
Thom Thumb
Silver Cloud
Dr. T. L. Meade (Blaze)
Pink Beauty
Smith Red

(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
Florida State University and United Stated Department of Agriculture, Cooperating
H. G. Clayton, Director

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs