AGRICULTURAL EXTENSION SERVICE
FOR THE HOME GARDENER
By S. S. WOLTZ and R. O. MAGIE
Gulf Coast Experiment Station, Bradenton, Florida
Fig. 1.-Photograph of a group of gladiolus varieties showing the selection
of color and form available.
Growing gladiolus in the home garden is easy and rewarding.
When in bloom the plants add a splash of color to the garden
and produce bouquets for use in the home. Selected varieties
are available in a wide range of clear, variegated and smoky
colors; they may be obtained from catalogs or your garden
The following commercial varieties are readily available to
the home gardener and are well adapted to Florida growing
W hite ........................
Pink ........ .............
Elizabeth the Queen
Spic and Span
GROWTH AND PROPAGATION
Flowers are grown from corms (commonly called bulbs) an
inch or more in diameter. Corms have four to eight buds in a
Iwhih - w* ('r
n 5-Seoloaty -Roots
Fig. 2.-Diagram of the lower part of a gladiolus plant at digging time
showing new and old corms, cormels and roots.
line across the top but usually only one or two buds will grow
and produce flower spikes. At the base of the corm is a circular
scar area left by breaking the "new" corm away from the old
or mother corm. Roots originate in a ring around the scar at
the base of the corm after the corm is planted.
Seven or eight leaves usually develop from a large corm.
Flowers may be expected 60 to 90 days after planting. Just
before the flower spike emerges, a new corm normally will start
to develop above the mother corm. Between the new and the
old corm, Fig. 2, appear secondary roots and cormels or bulblets.
Cormels may be planted to increase the corm stock of a
variety. They have a longer dormant period than corms and
do not germinate as evenly. Cormels are planted about two
inches deep, about 20 per foot of row to produce planting stock,
which are in turn planted to produce large corms or flowering
Gladiolus may be planted in frost-free areas of Florida at
any time of the year. In areas where killing frosts occur, the
corms should be planted for the spring season after the danger
of frost has passed. Fall plantings in northern Florida should
be made early enough to allow flowering before killing frosts.
(--4-- -- - --
So\ that Soil that Aoes iot
Arsons q.c%\0 4dva-M auv\\
Fig. 3.-Cross-section of beds showing how to plant corms in well drained
soil, left, and moderately drained, right.
Select a planting area on a well-drained soil in a sunny loca-
tion. If in doubt about the acidity of your soil, take a repre-
sentative sample to your county agricultural agent. If the soil
is too acid (pH below 5.5), apply liming material to raise the
pH to 5.5 or 6.0. Work the soil thoroughly about six weeks
before planting and remove all weeds and trash. Cultivate as
required to prevent new weeds starting up and to keep the soil
in planting condition. Mark off beds or rows in the planting
design desired. In well-drained or very sandy soils, prepare
a two or three inch trench, Fig. 3, for planting. If the soil
contains considerable clay or organic matter which retards
water movement, place the corms on the surface along the de-
sired line. Set the corms firmly into the soil, four to six inches
apart in rows that are two to three feet apart. Place three to
five inches of soil over the corms as a hill or bed to support the
plants. When planting is finished, rake in a commercial fertil-
izer such as 4-8-8 or 6-8-8 on the sides of the beds, but not
directly over the corms. Use about 21/ pounds per 100 feet of
row. Water the area to dissolve the fertilizer.
By selecting varieties or planting at intervals for several
weeks it is possible to provide flowers over a longer period.
CULTIVATION AND WEEDING
Keep weeds and competing plants at least 12 to 18 inches
away from the gladiolus plants. Hoeing or cultivating by skim-
ming the surface of the soil removes the small seedling weeds
before they become too large. Shallow cultivation causes less
damage to roots. Hill soil up around the plants to provide
support. Constant attention to the weed problem is rewarded
by better flowers and new corms, as well as less trouble in
Soils of high native fertility do not require any fertilizer in
addition to the planting application. A single sidedressing of
a commercial fertilizer such as 4-8-8 or 6-8-8 at 21/ pounds per
100 feet of row is suggested for soils of medium fertility five
weeks after planting. Three sidedressings at two-week intervals
after planting will be required for very sandy soils. Spread the
fertilizer on both sides of the row about six inches from the
plants and work into the surface soil without disturbing the root
system. The soil should be moist when the fertilizer is applied.
Water well after fertilizing to carry the fertilizer into the root
Gladiolus require ample water to produce good flowers and
corms, but the soil should be well drained for best results. If
rainfall is inadequate it may be necessary to water once or twice
a week, depending on soil texture. Moisten the root zone thor-
oughly when watering.
DISEASE AND PEST CONTROL
Diseases may be troublesome in wet weather on a few va-
rieties, but some garden varieties are resistant to disease. Ex-
cept for controlling insects, some gardeners grow gladiolus
without troublesome or expensive control measures. The most
important step in growing large flowers is to start with healthy
corms. Corm rot diseases are carried on the corms and trans-
ferred to the soil where they cause trouble in future plantings.
Disease losses may be minimized by purchasing clean, bright
corms. Small corms, one inch in diameter, are usually healthier
than larger corms. Dull, dark husks indicate old corms which
might carry diseases. If, in a lot of 100 corms, there are more
than two or three shriveled by rot or if the roots have grown
out far enough to be killed back, poor flowers and rotting of
corms after planting may be expected.
Before planting, remove husks from the corms and discard
those with disease spots that cannot be peeled out easily and
cleanly. Soak for two hours in eight ounces of "Merthiolate"
antiseptic diluted with 1 gallon of water. Keep solution away
from children and animals and wash hands with warm water
and soap. Instead of soaking, corms may be dusted by shaking
them in a large paper bag with preparations containing Arasan
or Captan (Orthocide). It is safer to use these dusts out-of-
doors. Some people are very sensitive to Arasan.
In warm weather plants should be sprayed or dusted each
week with chlordane or dieldrin to control thrips and chewing
insects. Follow the manufacturers' directions carefully. Chew-
ing insects in the soil are controlled by raking in one ounce of
40 percent chlordane wettable powder per 100 square feet before
planting. These insecticidal dusts or powders may lose their
ability to kill the insects after being stored for more than a few
If disease spots show up on leaves or flowers, spray once a
week with zineb or maneb to prevent their spread to healthy
plants. Use 1 ounce of the wettable powder in 3 gallons of
water and add 1/ teaspoon of any liquid detergent. Keep the
plants dry as much as possible to reduce disease spread.
Since root and corm diseases build up rapidly in the soil from
season to season, it is important to plant gladiolus, whenever
possible, in new parts of the garden each year. Diseases and
pests carried in the soil, as well as most weeds, may be con-
trolled by treating the soil with Vapam or Crag Mylone two
weeks before planting. Follow the manufacturer's directions
and cautions carefully. It is especially important to keep the
soil moist one week before treatment and cover the soil with
heavy paper or plastic sheet immediately after treatment to
confine the toxic gases for a few days. Another method of con-
trolling soil pests is to hire a commercial operator to apply the
deadly methyl bromide gas with special equipment.
CUTTING THE FLOWERS
Allow the lower floret or two to open fully before cutting
the spike for home use. Leave at least four leaves on the plant
when cutting so the corm will develop to a good size. To obtain
long stems, slip a sharp, narrow-bladed knife down one side of
the stem to about three or four inches above the ground, turn
the blade to cut the stem and bring the knife carefully up
the other side of the stem so as to avoid undue damage to the
leaves. If long stems are not desired, the stems may be cut
to the length needed. Spikes allowed to open on the plant
should be removed when they become unsightly by cutting
where they emerge from the leaves.
Gladiolus will last about a week in the home. Vases should
be kept clean and free of bacterial slime. Use one-quarter tea-
spoonful of Clorox or similar bleach in the water to control bac-
teria. Change the water every third day and cut off an inch or
more of the base of the stems at that time.
DIGGING THE CORMS
Dig the new corms about six weeks or more after flowering
or soon after the leaves turn brown. Darkening of most cormels
or bulblets to a brown or light tan color indicates that the
corms are ready to be dug. As you dig, cut off the tops close
to the corms.
After being dug, corms should be cured as quickly as pos-
sible by drying. Place them in trays or boxes under a shelter
so that maximum air circulation is provided. The new corms
will separate easily from the old after about two weeks of cur-
ing; separation becomes more difficult as storage time increases.
Store the corms in a cool place, preferably at 40 to 50 degrees.
Examine the corms after about three months for signs of root
buds around the base of the scar. If a ring of buds is present,
the corms are ready to plant again. Otherwise, return them to
storage until buds develop. The roots will develop more quickly
if the corms are held in a warm place for several days after
one to three months in cold storage.
Instead of digging and storing, some gardeners prefer to
leave the corms in the ground, simply cutting the dead tops off
the plants and allowing the new corms to sprout at their leisure.
Leaving the corms in the ground year after year usually results
in a reduction of flower quality.
The following points are most important in growing gladiolus
satisfactorily: (1) Select clean, bright corms of the desired
varieties; (2) plant in a sunny, well-drained location; (3) fertil-
ize at planting and repeat one to three times if the soil is not
very fertile; (4) water as required to keep the soil moist but
not water-logged; and (5) spray the plants when necessary to
control insects and diseases.
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. O. Watkins. Director