AGRICULTURAL EXTENSION SERVICE
Circular 171 October 1957
The garden amaryllis, Amaryllis vittatum (Hippeastrum vit-
tatum), A. belladonna, and A. reginae and their hybrids, are
members of the Amaryllidaceae family. Native to South America
and South Africa, many amaryllis grown today are hybrids of
native varieties and are highly prized for their large flowers.
The lily-like or bell-shaped flowers are red, pink, white and com-
binations of these colors.
Amaryllis are grown in the open field or in beds and borders
around the home. They are excellent landscape subjects for use
as individual specimens, in mass plantings, in beds or as part of
the border planting around home grounds, and in park plantings.
Those planted in the garden should be set so that the top of the
bulb is just covered with soil.
It is not necessary to dig each year or to "dry off," as com-
monly believed. It is better to dig, separate, and replant each
year as an aid to uniform flowering and larger flowers. This
practice also aids in reducing disease and insect pests, since un-
healthy bulbs can be graded out and destroyed at this time.
CARE AND FERTILIZATION
Amaryllis will grow in any good, well-drained soil. They
should be given an ample supply of moisture, i.e., water thor-
oughly to moisten soil 10 to 14 inches deep, then allow to dry
out before watering again. Low nitrogen fertilizer, such as
5-10-10 or 3-9-9 formulas, should be used, since high nitrogen
fertilizers tend to promote vegetative growth at the expense of
flowering. Fertilizers should be applied when the soil is being
T. J. Sheehan, Asst. Ornamental Horticulturist; H. N. Miller, Plant
Pathologist; S. H. Kerr, Assistant Entomologist, Agricultural Experiment
prepared at the rate of 11/ pounds per 100 square feet or per
100 feet of row for old soil and 3 pounds per 100 square feet for
new soil. For established plantings, two or three fertilizer ap-
plications using 1 pound per 100 square feet or 100 feet of row
produce better results than one heavy application.
Amaryllis can be forced into flower in six to eight weeks in
the greenhouse or in the home at any time during the year. A
little more time may be required for bulbs growing outdoors to
come into flower because of lower or fluctuating temperatures.
Amaryllis for forcing should be potted with one-half to two-
thirds of the bulb above the soil to induce early flowering.
Amaryllis can be propagated by either seed, offsets or cuttage.
Since seeds do not always produce plants similar to their parents,
most named hybrids and selected strains are propagated by cut-
Seed pods of amaryllis develop rapidly and are mature within
four to five weeks after the flower has been pollinated. Pods
should be picked as soon as they turn yellow and begin to break
open. Seed should be removed from the pod, allowed to dry for
a few days and planted immediately in flats or beds in a well-
drained soil. The seed area always should be partially shaded.
Uniform and constant moisture and good aeration aid in in-
creasing germination, hence soggy soil and poorly drained soils
should be avoided. Coarse sand, vermiculite or charcoal may be
added to the soil to improve drainage. The amount of light
should be increased following germination until the plants are
receiving full sunlight-more sunlight means more food for
storage in the bulb. The seedlings should be ready for spacing
out in nursery rows a year after planting.
The bulbs may be cut vertically (Fig. 1) into as many as 60
pieces. Care should be taken that each piece has a portion of
the stem tissue or basal plate of the bulb attached to the scales.
The best time for the cuttage is from July to November, after
the bulbs have made their full growth following flower production.
Bulbs cut in the spring, immediately after flowering, usually give
poor results as propagating material. The wedges should be
dusted with ferbam or thiram to retard diseases and planted im-
mediately in a mixture of peat and sand or other porous, reason-
ably sterile media in flats or in a bed.
Fig. 1.-Amaryllis bulbs showing mother bulb and offset (left), typical bulb (center) and vertical section showing bracts and
basal plate (right).
In a warm, humid atmosphere, small bulblets will begin to
form between the scales of cut pieces in about 3-4 weeks and
these will usually be ready for potting or planting after one
growing season. New bulbs will bloom within two or three years
in Florida, whereas it may take as many as five years for them
to reach the flower stage in cooler sections of the country.
Amaryllis bulbs are usually marketed when they reach flower-
ing size. Flowering is related to bulb size, larger bulbs producing
larger flowers. Bulb grades, based on circumference, are Exhibi-
tion, Selected and Field-run.
After the tops stop growing and the leaves are turning yellow
or brown-in late September and October--dig the bulbs and
remove the offsets. You can then set out young offsets in rows
or beds. In general, two to three years are required before these
offsets will attain flowering size. When the plants are dug, cut
off the leaves about 11/2 inches above the top of the bulb and
cut back the roots to within 2 inches of the bulb. Commercial
growers cure their bulbs for 30 days by air-drying them in trays
in a shady place to encourage the formation of a protective coat-
ing on the bulb so that they can be shipped and handled with less
loss or damage. The bulbs are packed 50 to 100 to a case and
marketed for October to January planting.
FAILURE TO FLOWER
Flower failure is one of the biggest problems in amaryllis cul-
ture and some common causes of failure are: (1) Prolonged dry-
ing of the bulbs. Actually the homeowner does not need to dry
the bulbs. Bulbs can be replanted immediately after digging
or if this is not practical, they can be stored in dry sand or saw-
dust to prevent excessive drying out. (2) Digging the bulbs be-
fore they are fully mature, i.e., before the leaves turn yellow in
the fall. (3) Too much shade, which reduces the manufacture
of food and causes even strong bulbs to decrease in vitality, pro-
duce smaller flowers and finally die. (4) Planting in rich soil
very high in nitrogen or over-fertilizing with high-nitrogen fer-
tilizers. Amaryllis is one of a group of plants that when grown
in a fertile soil or one with a high nitrate content, tends to vege-
tate profusely. It will use food manufactured by the leaves to
produce new leaves and shoots instead of accumulating and stor-
ing food in the bulb which would increase the vigor of flowering
and growth the following year. This problem can be overcome
by using fertilizers low in nitrogen, by planting in less fertile
soil and not overwatering during the late stages of growth.
:::. .:.: .... .
Fig. 2.-Diagrammatic sketch of amaryllis leaves showing normal (left),
red blotch (center) and mosaic (right).
Diseases are not too serious a problem in growing amaryllis,
but there is at least one which occurs occasionally on amaryllis
in Florida. This disease is referred to as "red-blotch" or leaf
scorch (Fig. 2). It is caused by the fungus Stagnospora curtisii.
Red spots are formed on leaves, flower stems and floral stems and
flower petals. The spots on the foliage are bright red to purplish,
small at first but often increasing to form large longitudinal
blotches. Leaves and flower stems attacked by this fungus are
characteristically deformed or bent at the point of attack. Flow-
er stalks of heavily infected plants may wither and dry up be-
fore flowers are produced. Dark reddish brown spots also occur
on the bulbs.
The fungus and spores of red blotch disease are carried on the
bulbs. Consequently, the leaves and flower stalks which push
up from infected bulbs may become infected. Badly infected
bulbs should be destroyed. It is helpful to treat bulbs before
planting by soaking them for two hours in a solution of bichloride
of mercury, 1:1000, or in a solution of formalin, 1 pint to 12 gal-
lons of water. The severity of the disease on the foliage can be
lessened by spraying the plants with neutral copper at the rate
of 1 ounce in 2 gallons of water. Plants grown in the green-
house should be provided with plenty of light, spaced for good
air circulation, and not syringed or too heavily watered.
Mosaic is a common virus disease of amaryllis. The leaves at
first have an indefinite yellow mottling which later becomes more
pronounced, showing small angular spots or streaks of yellow
and dark green color. Red streaks may appear on infected plants
from secondary causes. The plants become more stunted each
year and leaves, flower stalks, and flowers-if the plants bloom-
are greatly reduced in size. This is a systemic disease and there
is no known control. Destroy all infected bulbs and plants.
Seedling plants of amaryllis may be attacked by one or more
of the root and bulb rot fungi such as Pythium spp. or Sclerotium
rolfsii, causing root and bulb rots. Although S. rolfsii may at-
tack large bulbs and plants of amaryllis, this is not common in
Florida. Attacks of this and other root-rotting fungi are con-
fined primarily to seedlings, where they cause rotting of the
bulbs or sloughing of the plant roots. Plants attacked become
chlorotic, grow poorly, wilt and eventually die. Succulent stems
may have black, sunken lesions at the ground line and the plants
may rot and fall over.
These diseases cannot be cured once they have become estab-
lished, but they can be largely prevented by starting the seed,
small bulbs or bulb sections in clean soil where disease problems
have not occurred or in soil that has been fumigated or treated
with steam. Small lots of soil can be sterilized by baking in an
oven at 1800 F. for 30 minutes. Methyl bromide at the rate of
4 pounds per 100 square feet or steam can be effectively used for
fumigating nursery soil or ground beds. Watering pots, flats or
seedbeds with a solution of a good fungicide will help keep these
diseases in check.
Amaryllis are not generally bothered by insect pests, although
occasionally certain insects may cause trouble. The lubber grass-
hopper Romalca microptera (P. de B.) (Fig. 3) finds amaryllis
a favorite host plant, especially when the grasshopper is in the
Fig. 3.-Lubber grasshopper, female (above) and male.
nymphal stage. Lubber grasshopper adults are large, reaching
about 2-21/2 inches in length. They have short wings and are
incapable of flight. The young grasshoppers are greenish-black
with a narrow stripe along the back. The front legs and sides
of the head are blood-red.
The caterpillar stage of the Spanish moth, Xanthopastis timais
Cram, also feeds on amaryllis. This caterpillar is about the same
size as the corn earworm. Dark in color, the caterpillar has rings
going around the body zebra-fashioned. For control of both
these insects use sprays or dusts of toxaphene or chlordane. To
make up the sprays put 3 level tablespoons of either 40 percent
toxaphene wettable powder or 40 percent chlordane wettable
powder in a gallon of water. Apply the insecticides when the in-
sects appear on the plants.
Another insect which feeds on amaryllis in Florida is the
bulb fly. The larvae of the fly bore around in the bulbs. The
feeding is usually not deep and not very damaging, but the ap-
pearance of the bulb is altered so that its sale value may be af-
fected. Bulb flies on other bulbous plants have been successfully
controlled by the use of insecticides applied at planting time, and
there is no reason to expect that the same methods would not
work with amaryllis. Aldrin and heptachlor have been very
helpful. The bulbs may be shaken and coated with aldrin or
heptachlor dusts prior to planting. The dusts can also be
applied to the bulbs after the bulbs have been set in the planting
furrow. Narcissus bulbs were protected when soaked in dilute
emulsions prepared with 100 gallons of water plus 2 quarts of
heptachlor emulsion concentrate or 3 quarts of aldrin emulsion
concentrate (concentrates which contain 2 pounds actual insecti-
cide per gallon). A 10-minute soak or longer was employed prior
to planting. Fungicides were combined with these dips.
Control recommendations for bulb mites on amaryllis are not
available, but preliminary studies on caladium tubers indicate
that a 20 to 30 minute dip in demeton (Systox) solution prior to
planting may be helpful. Use 1 pound actual demeton (2 quarts
of emulsion concentrate containing 2 pounds actual demeton per
gallon) in 100 gallons of water. Caladium tubers given a coat-
ing of parathion by shaking them in a container with 15 percent
parathion wettable powder just prior to planting were also af-
forded helpful mite control.
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