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
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
A. R. Chase, R. T. Poole and L. S. Osborne
University of Florida, IF S. f: i .
Agricultural Research and Educati n rte- "
AREC-A Foliage Plant Research Note RH-1984-I
JAN 28 693
Ferns have always been an important segment o the foliage industry.
The Boston fern, Nephrolepis exaltata, was one of t pffr t er3n;
commercially for export and there are now many othe iIrnds .. i..
Bird's-nest fern, produced and sold in large quantities. Bird's-nest fern,
Asplenium nidus, is a large epiphytic fern, with erect, simple, wavy, bright
green leaves which can reach lengths of 4 feet. Asplenium nidus
'Crispafolium', the wavy bird's-nest fern, is similar to Bird's-nest fern
but fronds are much wavier.
Asplenium are produced from spores. Sphagnum or peat moss are good
substrates for spores, but very acid peat moss is improved by the addition
of 100 grams of dolomite per cubic foot of peat. Germination should take
place in about 2 weeks if temperatures are 70-800F. Only fresh spores
should be used. High humidity can be maintained by covering flats with
glass or polyethylene, but intermittent mist 15 sec/30 min during daylight
is preferred. If glass or polyethylene is used, the cover should be removed
4-6 weeks after sowing, and the young fern misted.
Mature fern can tolerate high light levels, but grow best between 2,000
and 4,000 ft-c. A potting medium high in organic content, e.g. peat:bark
(2:1 by volume), that has a high water holding capacity and good aeration
produces attractive fern. The benefits of additional micronutrients are
questionable and if added should be supplied at low rates. Bird's-nest fern
apparently get sufficient micronutrients from irrigation water and potting
medium. Although fern are commonly grown in highly acidic soils, recent
research indicates a pH of 5.0 to 5.5 is preferred. Addition of 3.5 pounds
of dolomite to a cubic yard of a mix with a large percentage of acid peat
will usually result in a mix with a pH of 5.0 to 5.5. The suggested
fertilizer level is 1200 lb N/A/yr from a 1-1-1 ratio fertilizer (about 2.5
Ibs N/1,000 ft /month). For constant fertilization 100-200 ppm N is
The best temperature for Bird's-nest fern growth is 70-900F. Tempera-
tures slightly outside of this range will not reduce plant quality but will
reduce growth rates.
Associate Professor of Plant Pathology, Professor of Ornamental Horti-
culture and Assistant Professor of Entomology, respectively. Agricultural
Research and Education Center, 2807 Binion Road, Apopka, FL 32703.
1) Flat or crinkled fronds
Symptoms Fronds are either very flat or extremely crinkled.
Control Although the crinkle or wavy habit of the fronds is influenced
by genetics, high light will increase severity of crinkling while
low light levels will cause fronds to be much smoother. Alter light
levels to achieve the desired frond flatness.
2) Multilobed fronds
Symptoms Fronds appear multilobed with indentations. Tips of fronds
may be crinkled and clear and sometimes necrotic.
Control Excessive amounts of fertilizer cause these symptoms. Re-
ducing the amount of fertilizer applied and leaching the potting
medium are recommended for this problem. In addition, plants may be
transplanted to new potting media and left unfertilized until normal
Symptoms Fronds have necrotic areas, usually on tips but sometimes
Control High applications of fertilizer is the most frequent cause of
tipburn. Reducing nutrients supplied and leaching the potting
medium will alleviate high soluble salts. Copper toxicity has also
produced necrotic edges on Bird's-nest fern. Pesticides containing
copper should be tested on a few plants to evaluate toxicity of each
material to be used on your crop.
Bird's-nest fern have two common disease pests; bacteria and nematodes.
Both problems'occur on plant foliage and symptoms are easily confused.
Diagnosis of foliar symptoms is very important since methods for control of
the two types of diseases are different. No information is available
concerning phytotoxicity of pesticides for control of these diseases of
1) Bacterial blight (Pseudomonas cichorii [=P. asplenii] or P. gladioli)
Symptoms Foliar lesions caused by these two bacterial pathogens are
essentially identical and the diseases can be treated together.
Small water-soaked, translucent spots form all over leaves. Lesions
enlarge rapidly to 1/8" in diameter and turn reddish brown with a
purple halo. When conditions are wet and warm, these lesions
frequently coalesce and may spread along veins encompassing large
portions of fronds. They can be vein delimited and sometimes
spread over one side of the leaf but do not cross the central leaf
Control Elimination of overhead watering is one of the most effective
control methods for bacterial blights. Pseudomonas gladioli blight
can be harder to control than P. cichorii blight even when leaves are
kept dry. Applications of bactericides are generally ineffective.
Always use pathogen-free plants for production and destroy sympto-
matic plants as soon as they are discovered.
1) Foliar nematode (Aphelenchoides fragariae)
Symptoms Lesions caused by foliar nematode are sometimes similar to
those caused by the bacterial pathogens described above. Small,
water-soaked spots form generally near the frond base. Lesions
rapidly turn brown to black and distortion of the fronds may occur
if large areas are infected. Affected tissue remains turgid and does
not collapse. Spread of the nematode within the leaves is usually
inhibited by large leaf veins making lesions somewhat angular and
Control The most effective control for foliar nematode on Bird's-nest
fern is destruction of infected plants. These organisms easily con-
taminate pots, potting media and bench surfaces which have organic
matter on them. Sanitation between crops can greatly reduce nematode
spread from one crop to the next. In addition, avoid producing
plants on the ground since it can be a source of nematodes as well.
The pests of Bird's-nest fern are of relatively minor importance, but
include caterpillars, fungus gnats, mealybugs, scales, and slugs. Mealybug
and scale infestations are typically the result of bringing infested plant
material into the greenhouse. In the control section for each pest a few of
the registered and effective pesticides will be listed. For a more complete
listing, please consult the references at the end of this report. No
information is available concerning phytotoxicity of pesticides for in-
sects and slugs on Bird's-nest fern.
1) Caterpillars (worms)
Symptoms Infestations are easy to detect because worms, their
excrement, and the damage they cause, are usually visible to the
unaided eye. Damage appears as holes in the center or along the
edges of leaves. Old damage can be distinguished from new by the
calloused appearance around damaged areas (worms are usually gone by
Control Lannate, Orthene, Dursban, Sevin, Dycarb or Ficam, Mavrik, and
Bacillus thuringiensis are effective in the control of various worm
2) Fungus gnats
Symptoms These small black flies are observed running around on the
soil surface or on the leaves. Larvae are small, legless "worms"
that inhabit the soil. The larvae spin webs on the soil surface
which resemble spider webs. Damage is caused by larvae feeding on
roots, root hairs, and leaves in contact with the soil. Wounds
caused by larvae may aid plant pathogen entry into the plant.
Control Reduce the amount of water applied where possible. Avoid
algae growth on walkways, benches, and cooling pads since larvae also
feed on algae. Soil drenches and soil-surface sprays of Diazinon
AG-500 and Vydate L or applications of granules (Temik 10G or Oxamyl
10G) are effective for controlling larvae. Adults do not cause any
direct damage, but are responsible for many consumer complaints to
growers. Adults emerge and fly around in retail shops, homes, or
offices and are therefore a nuisance.
Symptoms Mealybugs appear as white cottony masses in leaf axils, on
lower surfaces of leaves and on roots. Honeydew and sooty mold are
often present; infested plants become stunted and, with severe in-
festations, the plant will die..
Control Systemic materials such as Cygon, Disyston, Metasystox-R, and
Orthene are preferred. In addition, Dycarb or Ficam appear to be as
effective as some of the systemic materials. Control of root
mealybugs is accomplished with insecticide drenches. Diazinon and
Vydate are the only insecticides registered for this purpose, but
both can cause phytotoxicity. When pesticides are applied to the
soil, care must be taken to assure that the pots have good drainage
and that no saucers are attached.
Symptoms Infested plants become weakened or stunted and die. Scales
can be found feeding on leaves, petioles, or stems. Most scales are
round to oval, light to dark brown in color and pinpoint to 2 mm
long. They are usually distinct from the plant material on which
they are feeding.
Control See Mealybugs
Symptoms Slug and caterpillar damage are similar and determining which
pest is present can be difficult. Generally, the culprit can be
found on close examination of the plant. Slugs often live.under
benches or in dark, moist protected places close to the damage.
These pests are nocturnal and can be found feeding at night.
Control Sprays or baits (Metaldehyde 50% WP and bait, and Mesurol
bait) applied to moistened soil around plants are effective.
Repetitive applications are necessary. Good sanitation with removal
of extraneous plant material and debris which might shelter these
pests aids in control.
1. Chase, A. R. 1983. Phytotoxicity of some fungicides used on tropical
foliage plants. ARC-Apopka Research Report, RH-83-2.
2. Short, D. E. 1978. Phytotoxicity of insecticides and miticides to
foliage and woody ornamental plants in Florida. Extension Entomology
3. Short, D. E., L. S. Osborne, and R. W. Henley. 1982. 1982-83 Insect
and related arthropod management guide for commercial foliage and woody
plants in Florida. Extension Entomology Report #52.
4. Simone, G. W. and A. R. Chase. 1984. Disease control pesticides for
foliage production. Extension Plant Pathology report #30.
Mention of a commercial or proprietary product or of a pesticide in this
paper does not constitute a recommendation by the authors, nor does it imply
registration under FIFRA as amended. Pesticides should be applied according
to label directions.