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RHAPIS
PALMS
Culitivated
Species & Varieties
Culture and Care of the "Ladies"
By Lynn McKamey
Rhapis
Gardens, P.O.Box 287, Gregory, TX 78359 Rhapis, known as Lady Palms,
can be found in homes and gardens throughout the world. The widespread popularity
of these multi-cane fan palms can be attributed to their adaptability to
a wide range of soils, climates, and environments. Uniquely, they are the
only ornamental palms to have named varieties (cultivars) in green and variegated
forms. While four species are well known as elegant landscape accents or
indoor ornamentals, others remain unknown to cultivation, awaiting collection
in remote areas of Southeast Asia. The genus can be divided into two
basic groups: The robust Chinese subtropicals which are native to Taiwan
and mainland China, and the smaller Indochinese tropicals indigenous to
regions in and around Thailand and Laos.
Rhapis excelsa and Rhapis humilis are the oldest cultivated Chinese
species, recorded as prized ornamentals in the Far East as early as the
17th Century. These are characterized by having large thick leaves on sturdy
canes 3/4" to 1 1/4" (2 to 3 cm) in diameter which grow more than
8' (2.5 m) tall. Rhapis subtilis from Thailand and Rhapis laosensis are
"20th century" species, being discovered and named by Odoardo
Beccari in 1910 and brought into cultivation during the last two decades.
These have thinner, smaller leaves on narrow canes less than 3/4" (2
cm) in diameter and seldom exceed 8' (2.5 m) in height. Other species were
named and described by Beccari and Max Burret during the first half of this
century, but remain unknown to the modern world of cultivated plants. However,
several of these may be grown by Japanese horticulturists as "misnamed
varieties" of R. excelsa and R. humilis. Obviously, the genus needs
further study to establish complete order. This difficult project is being
undertaken by Dr. John Dransfield and Laura Fitt of the Royal Botanic Garden,
Kew, England.
Cultivated Species of Rhapis
Rhapis are some of the easiest palms to grow, but each species has its
own particular environment and culture requirements; no two are alike.
This idiosyncrasy provides versatility to the genus; wherever you may
live, at least one of the species will thrive in your house or landscape.
Lady palms can be propagated by division or seed, depending
on species. Rhapis are dioecious, requiring both male and female plants
for successful pollination. R. excelsa and R. subtilis seed are being
commercially produced; however, female R. humilis and male R. laosensis
are unknown in cultivation; as a result these species must be propagated
by division.
Rhapis
subtilis "Thailand Lady Palm"
 Rhapis subtilis
was introduced into cultivation by Watana Sumawong of Bangkok during the
late 1960s. At that time, Thailand Lady Palm was thought to be a miniature
form of R. humilis and was distributed commercially under that name until
1984 when it was recognized by Dr. Dransfield and Ms. Fitt to be Beccari's
Rhapis subtilis.
"Thailand
Lady Palm" is a small species, seldom exceeding 6' (2 m) of height.
Canes are narrow with neat smooth fiber, brown in color. Offshoots have
stiff, brittle roots and sucker close to the main cane, making division
almost impossible. Since males and females flower prolifically, abundant
amounts of seed are available.
At least two, if not three forms of R. subtilis exist.
The tallest type has leaves with broad segments which slightly resemble
R. excelsa.; a second form has tiny canes, small leaves with finely divided
segments, and slowly grows 2' to 3' (1 m) tall as shown in the photograph
above. A third type appears to be a combination of the others. Cross pollination
of these different forms may cause the wide variation in seedlings and
mature plants. Unlike the blunt tipped R. excelsa, all R. subtilis have
pointed leaf tips.
Being a tropical,
R. subtilis requires high humidity and abundant moisture. While all Rhapis
can attract scale insects, this is the only species severely affected by
spider mites. It has a temperature range of 32 to 90 degrees F (0 to 32
degrees C), but prefers 60 to 80 degrees F. Thailand Lady Palm thrives in
humid, tropical climates, but seldom adapts to hot dry regions or cool subtropical
areas. It can be difficult as a houseplant.
Rhapis
laosensis "Laos Lady Palm"
First discovered
and named by Beccari more than 70 years ago, this small Lady Palm was brought
into cultivation during the 1960s by the late David Barry of California.
The few specimens in America are all female divisions of his plants and
they have not yet been critically identified as R. laosensis. Canes are
pencil thin and as with R. subtilis, have slick neat fiber. Thin leaves
with wide segments curve downward providing a very graceful effect. One
of the oldest cultivated specimens is displayed at Fairchild Tropical Gardens
in Miami and stands almost 6' (2 m) tall.
Laos
Lady Palm is relatively easy to divide, but remains scarce in supply.
Culture is not difficult - thoroughly water when slightly dry and keep
temperatures between 30 to 90 degrees F (-1 to 32 degrees C). R. laosensis
grows best in humid tropical areas, but will adapt to warm subtropical
climates.
Rhapis humilis "Slender Lady Palm"
Native to China,
this subtropical is the tallest of all Rhapis, often exceeding 18' (6 m)
in height. Large leaves with many narrow segments envelop slender canes,
creating the name "Slender Lady Palm".
Some of the first
imported into America in the early 1900s are still majestically growing
at The Huntington Botanical Garden in San Marino, California. Primarily
used as towering landscape specimens on the American west coast, R.humilis
thrives in cool subtropical climates with temperatures from 18 to 90 degrees
f (-7 to 32 degrees C). Those grown in tropical regions suffer in hot summer
heat and can exhibit slow growth and loss of vigor.
Only
male plants are known in cultivation, therefore, propagation must be by
division. Small container specimens under 6' (2 m) tall are scarce since
roots are brittle and slow to establish; as a result, clump divisions
are more successful than single cane separations.
Rhapis excelsa "Large Lady Palm" and "Miniature Lady Palms"
Rhapis excelsa
is the most well-known and widely cultivated species, easily adapting to
most interiors and tropical or subtropical landscapes throughout the world.
It has a multitude of named varieties in green and variegated forms.
Historically,
R. excelsa have been used as classic ornamental palms for more than 300
years. They were cultivated by the Japanese elite in the early 1600s, introduced
to Europe in 1774, and became prized American "parlor palms" during
the 1850s. The popularity of this species can be attributed to its ease
of care, durability, insect resistance, and long life.
Rhapis excelsa
consists of two groups: the common "Large Lady Palm" grown from
seed or divisions, and the highly refined "Miniature Lady Palms"
developed by Japanese enthusiasts into named varieties by selective cloning.
The "Large
Lady Palm" can grow to more than 14' (4 m) of height. Unlike R. humilis
which has tall, slender clusters of stems, R. excelsa clumps can gain enormous
width, often having a diameter as wide as their height. In 1939, Fairchild
Tropical Gardens of Miami planted twelve single cane divisions 6' (2 m)
apart; today, these multi-cane palms stand in a 10' to 12' (3 to 4 m) tall
hedge which is more than 9' (3 m) wide and 80' (26 m) long.
Large thick leaves with blunt tips have wide segments,
giving R. excelsa its occasional name "broadleaf lady palm".
Its sturdy canes are covered with coarse, dark brown fiber. This species
tolerates tropical and subtropical temperatures from 20 to 100 degrees
F (-5 to 38 degrees C) and will accept both humid and dry climates. It
is a prolific producer of rhizome offshoots which adds fullness and provides
an easy method to increase numbers by division. In addition, seed is occasionally
available.
The green and
variegated Japanese cultivars of Rhapis excelsa, collectively known as "Miniature
Lady Palms", were developed through selective cloning of choice, unusual
specimens from Taiwan. Each named variety has a unique leaf shape and growth
habit. Because of a preference for miniature plants, the Japanese propagate
the slowest growing strains and further "dwarf" the palms by restricting
root systems in tiny pots, using course sand or small gravel, and limiting
fertilizer applications. Below, the 'CHIYODAZURU' in a 5" by 7"
(13 by 18 cm) bonsai pot is 10 years old and only 24" (60 cm) tall.
However, if these cultivars are given unrestricted growth conditions, some
"miniatures" such as 'Koban', 'Daruma', and 'Tenzan' can eventually
exceed 8' (3 m) in height. When I wrote the book Secret of the Orient (McKamey
1983), the estimated maximum height of Japanese cultivars was 4' (1.3 m);
at Rhapis Gardens, we now have many specimens over 6' (2 m) tall. This interesting
discovery has lead to the nickname "Texas sized dwarfs," although
I am sure others can grow them just as large! However, some cultivars such
as 'Kodaruma' and 'Gyokuho' are true dwarf Ladies by staying relatively
short and reaching only 4' of height after 30 years such as the ones shown
below.
Large thick leaves
with blunt tips have wide segments, giving R. excelsa its occasional name
"broadleaf lady palm". Its sturdy canes are covered with coarse,
dark brown fiber. This species tolerates tropical and subtropical temperatures
from 20 to 100 degrees F (-5 to 38 degrees C) and will accept both humid
and dry climates. It is a prolific producer of rhizome offshoots which adds
fullness and provides an easy method to increase numbers by division. In
addition, seed is occasionally available.
The green and
variegated Japanese cultivars of Rhapis excelsa, collectively known as "Miniature
Lady Palms", were developed through selective cloning of choice, unusual
specimens from Taiwan. Each named variety has a unique leaf shape and growth
habit. Because of a preference for miniature plants, the Japanese propagate
the slowest growing strains and further "dwarf" the palms by restricting
root systems in tiny pots, using course sand or small gravel, and limiting
fertilizer applications. Below, the 'CHIYODAZURU' in a 5" by 7"
(13 by 18 cm) bonsai pot is 10 years old and only 24" (60 cm) tall.
However, if these cultivars are given unrestricted growth conditions, some
"miniatures" such as 'Koban', 'Daruma', and 'Tenzan' can eventually
exceed 8' (3 m) in height. When I wrote the book Secret of the Orient (McKamey
1983), the estimated maximum height of Japanese cultivars was 4' (1.3 m);
at Rhapis Gardens, we now have many specimens over 6' (2 m) tall. This interesting
discovery has lead to the nickname "Texas sized dwarfs," although
I am sure others can grow them just as large! However, some cultivars such
as 'Kodaruma' and 'Gyokuho' are true dwarf Ladies by staying relatively
short and reaching only 4' of height after 30 years such as the ones shown
below.
Growth rates
of Rhapis excelsa vary with culture and environment. In commercial production
with 80% shade and subtropical temperatures, the slow growing Miniature
varieties can add 3" to 6" (7 to 15 cm) of height each year, whereas
Large Lady Palms usually increase 8" to 12" (20 to 30 cm). If
Rhapis are grown indoors as houseplants, these rates decrease considerably.
Although some
young seedlings of common R. excelsa may first resemble certain named varieties,
most will eventually develop the same basic "standard" appearance
and leaf shape. In contrast, the named varieties will maintain their distinctive
characteristics, a result of long-term selective cloning.
Variegated Rhapis
are seedling sports. Within a random group of 10,000 seedlings, perhaps
only five will sprout striped leaves, and of these just one may remain a
stable plant and retain a good striping pattern. This is then propagated
by division to provide the basis of a new variegated cultivar. In Japan,
only a few named varieties display perfect stripes on every leaf; most have
random striping patterns - no two are exactly alike. Usually, new offsets
will carry the striping habit of the leaf directly above on the "mother"
cane. Rhapis excelsa 'Zuikonishiki' is one of the most popular variegateds,
being easy to grow and a prolific producer of offshoots. However, it generally
yields less than 40% choice pups with the other 60% being an interesting
assortment of those having more green than white stripes or more white than
green. The rare, very finest variegated pups are classified 'Ayanishiki'
whereas those with mostly white leaves are renamed 'Zuiko-Lutino' . The
creamy white stripes in these cultivars contain "golden chlorophyll"
which can support growth and sustain the plant. The 'Zuiko-Lutino' shown
below is in an elegant 7" (18 cm) Japanese Nishiki Pot with a "wave
and bird" design.
Other varieties
such as 'Kotobuki' shown below have stripes with albino cells which are
extremely sensitive to strong light or extreme heat. These types are best
grown in shaded, cool areas.
On a stable plant,
a variegated pattern cannot be experimentally controlled or changed, but
brightness of stripes on some cultivars can be enhanced with proper culture.
An example is 'Chiyodazuru', one of the most popular in Japan, which has
narrow stripes on green leaves. Intense sunlight and heat can fade leaves,
or strong fertilizer can mask, but not delete, the stripes. For best color,
this variety needs cool temperatures, medium light, and medium fertilizer
rates - easily accomplished by growing indoors or in dense shade.
Other Japanese Cultivars of Rhapis
Japanese horticulturists
have developed more than 100 named cultivars. While most of these are varieties
of R. excelsa, called KANNONCHIKU, others are green and variegated cultivars
of SHUROCHIKU, translated "Rhapis humilis". Although these will
eventually reach 6' (2 m) in height and do resemble a delicate, dwarf form
of the towering R. humilis grown in California, they may prove to be an
Indochinese species more closely related to R. subtilis. Several inflorescences
await inspection by Dr. Dransfield and Ms. Fitt, so the mystery may soon
be solved.
Those
familiar with Japanese cultivars may have noticed or obtained Ladies such
as Rhapis 'Himedaruma' classified as a KANNONCHIKU (R. excelsa); however,
it is noted in the book The Miniature Palms of Japan" to be of the
"imported group" (i.e. from places other than Taiwan and southern
China). On inspection, 'Himedaruma' appears to be R. laosensis as is another
variety 'Otohime'. I suspect, therefore, that some of the curious cultivars
of KANNONCHIKU could be identified as some of the lost species of Beccari
and Burret. Time and taxonomy will tell.
Rhapis
are a fascinating group of palms, having captured the love and admiration
of plant collectors for centuries. The charm and elegance of this diverse
family of Lady palms provide unlimited choices for everyone... anywhere.
CULTURE TIPS FOR ALL RHAPIS
LIGHT: In landscapes, all species of Rhapis prefer filtered
light or partial shade. Locate in east, south, and north exposures or under
a canopy of tall trees. Placement in full sun without protection will cause
unattractive yellow-green leaves, stress, and slow growth. Indoors, all
Rhapis grow best in bright, indirect light near a window or skylight. R.
excelsa is the most adaptable to low light areas.
WATERING: Rhapis should be thoroughly watered by soaking
or drenching the entire root system. R. subtilis must be kept constantly
moist; if it dries, it will decline or die. R. excelsa, R. humilis, and
R. laosensis should be allowed to become almost dry between thorough irrigations.
Twice each year, potted Rhapis should be drenched several times (leached)
to flush impurities and excess soluble salts.
SOIL: Rhapis will grow in almost any well-drained soil,
but prefer a mixture rich in humus (pH 5.5 to 7). Pot in African violet
type mix or plant slightly above ground level, amending your garden soil
as needed. All roots and the base of canes should be covered to retain moisture
and stimulate the addition of new offshoots.
POTTING: Lady Palms prefer to be slightly root-bound.
Soil density should be firm - not loose, not packed - and allow water to
slowly filter through.
FERTILIZER: All Rhapis are relatively slow-growing plants
and need very little fertilizer. As a guideline, apply only 1/2 the recommended
rate required by other plants in your home or landscape. Let leaf color
be a guide: rich green indicates that fertilizer levels are adequate; apply
nutrients when a slight overall yellowish color is detected.
Rhapis
can suffer from trace element deficiencies which produce yellowing leaves,
distorted new growth, or general decline. Since the exact cause of a deficiency
can often be hard to determine without laboratory tests, use a weak solution
of fish emulsion whenever a problem is suspected.
A WARNING FOR EXCESSES: Rhapis and many other palms
can be highly sensitive to excess boron, fluoride, and chlorine in water
supplies, which will cause fast spreading black tip burn. Use the purest
water available until the problem is corrected.
BROWN TIPS: Slight brown tip fringe is common on all
Rhapis. Black tip burn is not typical and can be caused from improper watering,
over fertilizing, and other excesses.
Damaged
leaf tips can be trimmed with serrated scissors (pinking shears). Cut
in line with the leaf tip, move the scissors slightly sideways and cut
again.
DRIED AND BROWN LEAVES: Leaf damage is usually caused
from extreme heat, allowing the palm to dry out, or not thoroughly watering
the entire root system.
PESTS: Scale is the enemy of all Rhapis; spider mites
are a major problem for R. subtilis. Since scale can hide in the fibrous
leaf bases, contact sprays such as malathion are seldom effective. A systemic
insecticide which is absorbed into the plant system provides the best protection
or control. Since spraying Rhapis in hot summer weather can cause leaf burn,
use a systemic insecticide labeled for soil application or spray only during
early morning hours.
ROOT ROTS: Rhapis are very resistant to pathogens; however,
Fusarium oxysporum, Pythium, Rhizoctonia, and Penicillium (pink rot) can
periodically infect Rhapis. Use a "broad spectrum" root fungicide
labeled as a soil drench to provide prevention or control.
LETHAL YELLOWING: Rhapis palms are not known to be susceptible
to this fatal disease. During the severe outbreak of L.Y. in Miami, Florida,
all species of Rhapis grown in the area remained completely unaffected.
FREEZE DAMAGE: Protected Lady Palms can often survive
temperatures below their recommended low. The tallest canes may be damaged
or frozen, but provide protection for lower, younger offshoots. In extreme
lows, all visible canes will die, but new offshoots may sprout by summer.
DIVISION: The best time to divide Rhapis is during spring
or early summer when the palms are actively growing. Single cane divisions
should have at least six leaves and several roots before being separated.
Pot into well drained soil using containers just slightly larger than the
root system. Remove several lower leaves on each cane to reduce stress.
Place in a humid area or mist daily until the palms resume active growth.
SEED: Be aware that R. subtilis seed looks exactly like
R. excelsa which matches Guihaia argyrata, a recently discovered Chinese
relative which sprouts grass-like leaves with silvery undersides (Principes
29 (1). To avoid surprises and a possible mixture of potluck palm seed,
commercial growers should know their seed sources.
Rhapis
usually flower during spring, need hand-pollination for best crop, and
are harvested in late winter. After cleaning the seed, lightly press into
well-drained soil and keep moist. Seed should sprout within 50 to 120
days. Immature seedlings of R. excelsa and R. subtilis look alike until
about two years of age when character leaves begin to distinguish one
from another.
AIR LAYERING: Yes, Rhapis excelsa can be airlayered.
VARIEGATEDS: Easy to grow, but require excellent culture
and good quality water for best appearance and growth. They prefer 70-90%
shade or indirect interior light, and temperatures between 60 to 80 degrees
R (15 to 26 degrees C) to maintain growth and vigor. Striped Rhapis are
slower glowing than green forms and require less fertilizer - too little
is far better than too much which may cause leaf burn and root damage.
LANDSCAPE USE: Rhapis excelsa adapts to most tropical
and subtropical landscapes. R. subtilis thrives in warm, humid regions.
R. humilis prefers subtropical landscapes with cool summer nights.
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