Rhapis palm

Rhapis Palms

Cultivated Species & Varieties - Culture and Care of the "Ladies"

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. 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.

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.

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.

Other varieties such as 'Kotobuki' 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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sources: myself, David Barry, John Dransfield, Yoshihiro Okita, Leland Hollenberg, Ed Green, The International Palm Society. Copyright 1989-1999 Lynn McKamey. Originally published in Principes Volume 33: 129-139 (No.3, July 1989). Reprinted by permission.<<<