Daniel Gill | 3/19/2015 7:36:00 PM
Through the ages, few plants have been as important to humans as palms in providing food, fuel, timber and aesthetic beauty. While most palms are native to tropical regions of the world, many types will adapt well to the mild winter climate found in south Louisiana. A few palms are reliably hardy in north Louisiana.
Several factors must be considered when choosing palms for Louisiana landscapes, but cold tolerance is, without a doubt, the single largest limiting factor in selecting palms. In order to be successful in growing palms, it is important that you correctly identify those that are native or adapt readily to our region. This bulletin will describe a variety of the hardier palms which can be grown in south Louisiana.
Classification and Physiology
Palms are classified as angiosperms in the subclass monocotyledons and in the family Arecaceae. Because they are monocots like bamboo and grasses, there are many physiological differences between palms and other trees that require different treatment when it comes to care and maintenance as well as transplanting.
Palms are considered woody plants that have solid stems or trunks. However, since palms are monocots this stem tissue is not differentiated into wood, bark, pith, or annual growth rings like most trees. Instead, palms have scattered bundles of vascular tissue distributed throughout the cross-section of the trunk. These vascular bundles make the trunks of palms strong and resistant to breaking. However, this structure prevents palm trunks from growing callus tissue over wounds in the trunk. Care must be taken to avoid wounding the trunk during digging, transportation and planting. The trunks of palms tend to be cylindrical in shape and do not enlarge in diameter every year like the trunks of typical trees. They typically do not branch. There is usually one main growing point known at the terminal bud where all leaves arise.
The root systems of palms tends to be fibrous, making them very sturdy and hard to uproot once well established; but at the same time, very easy to transplant.
A group of plants called cycads are often confused with palms. All cycads are tropical or subtropical species that resemble palms in overall appearance; however, this is where the similarities end. While palms are angiosperms (flowering plants), cycads are gymnosperms (cone bearing plants), which also include conifers (pine, cedar, cypress) and the ginkgo tree. While technically a woody plant, cycads possess a pachycaul stem – a thick soft stem or trunk made up of mostly storage tissue with very little true wood.
The most common cycad found in Louisiana is the sago palm (Cycas revoluta, also called king sago). This cycad is a native of Japan and is hardy to about 15 degrees F. Leaves are 2-3 ft. long (can be larger on older plants) and are divided into many narrow, needle like segments.
Even though they are not actually related, the culture of the sago palm is similar to the culture of true palms discussed in this publication.
Palms in Louisiana
Commonly grown palms vary tremendously in height depending on the species. The CanaryIsland date palm (Phoenix canariensis) grows to be 50-60 feet, while the native palmetto (Sabal minor) usually does not grow taller than 6 feet.
There are a variety of hardier palms that have been used in south Louisiana landscapes, particularly in the New Orleans area. A survey in the late 1990s found 14 genera of palms comprising 21 species growing in landscapes across south Louisiana (Table 1). An extensive survey of palms in the New Orleans area was done in the summer of 1990 after the disastrous freeze of December 1989. Based on a statistical analysis of the data collected on palms that survived or died, less than half were found cold tolerant enough to be statistically reliable for planting. Those recommended as hardiest for south Louisiana are Blue Hesper(Brahea armata), Bamboo Palm(Chamaedorea microspadix), Canary Island Date Palm(Phoenix canariensis), Needle Palm(Rhapidophyllum hystrix), Texas Palmetto(Sabal mexicana), Dwarf Palmetto(Sabal minor), Cabbage Palm(Sabal palmetto), Saw Palmetto(Serenoa repens) and Windmill Palm(Trachycarpus fortunei).
Those species that were found to be less reliably cold hardy, include Pindo Palm(Butia capitata), Mediterranean Fan Palm(Chamaerops humilis), Chinese Fan Palm(Livistonia chinensis), Lady Palm(Rhapis excelsa), Queen Palm(Syagrus romanzoffiana), Petticoat Palm(Washingtonia filifera), and Washington Palm(Washingtonia robusta).
The hardiest palm species recommended for north Louisiana include needle palm, Texas palmetto, cabbage palm, dwarf palmetto, saw palmetto and windmill palm.
TABLE 1. Palm species found growing in south Louisiana
Blue Hesper or Windmill Palm
Jelly or Pindo Palm
Mediterranean Fan Palm
Chinese Fan Palm
CanaryIsland Date Palm
Senegal Date Palm
Transplanting and Planting
The best time to transplant or plant a palm is from late April through August. This is because the soil is warm and encourages the roots to grow vigorously. However, it must be noted that many palms are not very tolerant of transplanting when they are young and the root initiation zone at the base of the stem is developing to its full potential. When obvious trunk development has taken place, transplanting can be most successfully achieved. Young plants without obvious trunks should only be transplanted from containers.
The roots of palm trees generally die back to the trunk when cut, and new roots regenerate from the base of the trunk. For this reason, palms are often moved with relatively small root balls. When transplanting the cabbage palm (Sabal palmetto), for example, roots may be cut to within one foot of the trunk. Root pruning six to eight weeks prior to transplanting any palm is advisable to allow time for needed root regeneration near the trunk.
However, research has shown that this is not true for all palms. So, before digging up a palm for transplanting, it’s a good idea to check and see if a larger rootball needs to be taken.
At time of transplanting, one-third to one-half of the older fronds should be removed from most species to reduce water loss by transpiration. Also, the ring of leaves immediately next to the bud should be removed to alleviate pressure on the bud. The remaining leaves should be gathered around the new emerging leaf and tied into place. This not only reduces transpirational losses, but also protects the bud. Rough handling of the palm or severe vibrations during transport can break the tender bud causing death many months down the road. It is also important to plant the palm as soon as possible after digging and to never allow the roots to become dry. All of a cabbage palm leaves can be removed at transplanting for better survivability.
Palms are also available container grown. Container grown palms are generally smaller plants, which makes it more feasible for home gardeners to purchase and plant these palms. Palms grown in containers are planted with their entire root system intact. Although generally smaller, they grow faster initially that palms that are field grown and dug.
The practice of filling the planting hole with peat moss, pine bark, manure, etc. is no longer recommended for palms, or any tree for that matter. Using these additives physically alters the immediate environment around the root zone causing the roots to avoid penetrating into the native surrounding soil. However, if an entire bed is being prepared for a raised bed, a good quality blended topsoil or garden soil can be used.
For hole preparation, dig the hole as deep and at least twice as wide as the root ball. The palm should then be placed in the hole with the top of the root ball even with the surrounding soil (remove container grown palms from their container). Do not plant the root ball lower than the surrounding grade. Thoroughly pulverize the soil removed from the hole to break up any large clods, and use this soil to fill in around the root ball. After the hole is filled in, water thoroughly to settle the soil and remove any air pockets. The area should then be covered with 2 to 4 inches of mulch, such as pine bark or pine needles, to help conserve moisture and discourage weeds. Apply a final soaking of water to settle the mulch and firm up the soil. It is also important to keep the soil in the planting hole evenly moist during the first several months by watering thoroughly every four to five days when there is no rain.
Bracing may be necessary for many tall palms to help stabilize them. The braces should never be nailed directly into the trunk as palms do not have the ability to heal wounds. Nail holes or other injuries invite pathogens. An insulated collar made of wood or metal can be used to support the trunk or ropes can secure the palm into place. The supports can generally be removed after about eight months.
Recommendations for fertilizing palms are generally based on research done in central and south Florida, and it is influenced by their unique soils and growing conditions. Soils in Louisiana generally contain more mineral nutrients and fertilization is generally not as critical to good health here. It’s always a good idea to have the soil where the palms are planted tested to determine nutrient levels when deciding what fertilizer to use (contact your parish LSU AgCenter Extension office). This will guide what type of fertilizer is used based on what is sufficient and what is lacking in the soil.
Research shows that palms do have a greater need for magnesium than many plants, and fertilizers specifically formulated for palms include added magnesium. Generally speaking, a suitable fertilizer for palms would include 10 to 20 percent nitrogen, 5 to 10 percent phosphorus, 10 to 20 percent potassium, 2 to 5 percent magnesium and .5 percent manganese and iron. This is often what you will find in fertilizers specifically blended for palms. If the soil has adequate magnesium, a general purpose fertilizer with a 3:1:2 or 3:1:3 ratio analysis would work well. Ideally, most of the nutrients should be in a slow release form. Follow package directions when determining the amount of fertilizer to use. Larger palms will require more fertilizer than young palms.
Florida recommendations may be to fertilize palms 4 to 6 times a year, but in Louisiana 1 or 2 applications should be adequate (most palms in Louisiana are growing well without much or any supplemental fertilization).
To encourage vigorous growth, fertilization should be done twice a year in mid April and again in mid June. Apply granular fertilizers by broadcasting the fertilizer from near the base of the trunk outward to several feet beyond the margins of the leaf tips. Irrigate thoroughly after fertilization. Tree spike fertilizers may also be used, but are expensive and have a tendency to concentrate the fertilizer into a small area of the root zone.
Nutrient deficiencies will produce noticeable symptoms. Nitrogen deficiency appears as a general yellowing of all the leaves. Potassium and magnesium deficiency affect the older foliage (it is normal for the oldest leaves to begin to deteriorate as a part of natural senescence). Magnesium deficiency will appear as orange to brown around the edges of the leaflets while the inner part is green. A potassium deficiency appears as orange or yellow spots. Manganese deficiency causes a condition known as “frizzle top.” The new growth emerges yellow or brown, twisted, stunted and deformed.
Pruning consists primarily of removing the lower, older fronds as they age and become unattractive. You cannot prune to control the height of palm trees. Decapitating a palm below the crown and leaves in an attempt to reduce the height will kill the plant.
Old flower and fruit stalks may also be pruned to improve the appearance of a palm. Most palms will eventually produce clusters of fruit. Where the falling fruit would be an issue, such as falling on patios, walkways, driveways or in pools, the flower stalk can be pruned away to prevent fruit from forming.
For those few palms that produce suckers at their base and form a clump of several trunks, such as the Senegal date palm (Phoenix reclinata) or the Mediterranean fan palm (Chamaerops humilis), the height of the clump can be reduced by cutting back the tallest trunks to ground level. The shortest trunks are retained.
Sometimes freezing weather will kill all of the fronds. If this should happen, do not do not immediately assume that it is dead. It is possible that the bud or growing point survived. Give the palm until the end of the summer after the freeze damage to send up new growth before making a decision to remove it. Look for new growth to occur at the center of the crown. If new growth is not present by August of the following summer, remove the palm. However, if new growth is observed, remove all of the dead fronds, if not done already, and the tree should eventually recover. On occasion, however, palms may start to send out new growth and then die.
The majority of palm species must be propagated by seed. This, along with their relatively slow rate of grow, explains why they are relatively expensive to purchase. Some palms may be propagated by separation of offshoots from the main trunk, an example being Phoenix reclinata (Senegal date palm). Some multi-trunked species may be propagated by division, such as Chamaerops humilis (Mediterranean fan palm) and Chamaedorea microspadix (parlor palm).
Propagation by seed is probably the easiest way to increase palm numbers. The following is a step by step procedure for propagation of palm seeds.
While palms are relatively pest free, there are occasions where they are attacked by insects and diseases. Some of the more common insect problems include, scale, spider mites caterpillars, mealybugs and leaf eating beetles. Termites have also been known to attack the trunk of older palms.
To control scale, spider mites and mealybugs, an application of paraffinic oil spray is recommended whenever the insect is present. To control caterpillars or leaf eating beetles, an application of carbaryl (Sevin) will be effective. For caterpillars alone, Bacillus thuringiensis (Dipel, Thuricide) is suggested.
A few leaf spot diseases may attack in this area and can be controlled by spraying with ornamental fungicides as soon as the leaf spot is detected. However, diseases are usually not severe in the South Louisiana area. Be sure to read and follow label directions for the use of any pesticides.
Contact your local county agent for help with diagnosing problems and determining proper treatment.
Although the total number of palm species that can be grown in Louisiana is relatively small, the few that can be grown certainly provide a tropical look to this area of the country. While the following list is a description of palms that are commonly found in south Louisiana, not all palms on this list are deemed reliable for planting due to the fact that some are not very cold tolerant.
Palm Species with Palmate (fan-shaped) Leaves
(1)Palmetto (Sabal minor): This plant is native to Louisiana and may be found from Texas to Florida and up to South Carolina. This palm is generally trunkless and shrubby and may reach from 6-8 feet tall. The leaves are 1-3 feet wide and fan shaped. The unarmed leaf stalks, or petioles, may be three feet long. The palmetto produces numerous white flowers on stalks from May to June, followed by black fruit 3/8 inch in diameter later in the year. Transplanting palmetto from the wild is often very difficult because of the subterranean trunk. Palmettos are relatively slow growing. Will grow in shady locations.
(2)Cabbage Palm (Sabal palmetto): Native to Florida, this palm may reach a height of 80-90 feet; but many only grow to 20 or 30 feet. The trunk height is variable. Sometimes the trunks may be covered with the crisscross pattern of old leaf bases;however, in the New Orleans area, most of the cabbage palms have smooth, thin trunks usually less than 12 inches in diameter. The leaves are fan shaped and may be 3-6 feet in length. The leaf stalk or petiole is unarmed and may be longer than the leaf itself. Often the petiole base is split. The flower stalk is 2-3 feet or more in length, producing numerous whitish flowers followed by global, shiny, black fruit, 1/3 inch in diameter. It also will adapt well to our wet, poorly drained soils. Cabbage palms are moderate in growth rate.
(3)Texas Palmetto (S. mexicana): This species of palm is native to northern Mexico and southern Texas and may reach a height of 60 feet. It is the largest of all Sabal palms grown in south Louisiana. The trunk is smooth, grayish and usually free of the leaf bases. The leaves are fan shaped and may be 6 feet long. The petioles or leaf stalks are 6 feet long and extend into the leaf. The flower stalks are shorter than the leaves. The fruit at maturity is about ½ inch in diameter, dark brown and somewhat flattened at the bottom. This palm is moderate in growth rate.
(4)Saw Palmetto (Serenoa repens): This clumping palm that forms thickets is native from South Carolina, southwest throughout Florida and westward to Louisiana. It may reach a height of 10 feet, but more commonly grows to about three feet. The leaves are fan shaped and are approximately three feet across. The leaf color varies from yellowish-green to blue-green. Saw Palmetto should do very well in south Louisiana. However, availability is scarce. They are slow growing palms.
(5)Petticoat Palm (Washingtonia filifera): This palm is native to southern California, western Arizona and northwestern Mexico. It may grow to a height of 50 feet. Often the dead leaves remain attached to the trunk giving the appearance of being skirted. If the leaves are removed, the trunk appears light gray and somewhat thicker than Washingtonia robusta. It may be three feet in diameter, but not enlarged at the base. The leaves may be six feet or more in diameter and fan shaped. The petiole or leaf stalk may extend six feet or more from the trunk, and the leaf base at the point of attachment may be six inches wide. The petiole is armed with prominent green teeth. The small numerous white flowers are followed by fruit 1/3 of an inch long, ¼ inch wide and lightly wrinkled. This palm is slightly more cold hardy than W. robusta. Both Washingtonia palms are fast growing with W. robusta being the fastest.
(6)Southern Washingtonia (Washingtonia robusta): This palm is native to northwest Mexico. It is the most commonly planted species of Washingtonia in Louisiana. The trunk may extend to 80 feet. It is usually more slender except for an expanded base. The trunk is reddish brown and a crisscross pattern of leaf bases may be evident, however not nearly as prominent as palmetto. The leaves are fan shaped, bright green and usually not as wide as W. filifera. The petiole is reddish brown and toothed. Both species of Washingtonia are difficult to distinguish. This Washingtonia is slightly less hardy than W. filifera.
(7)Windmill Palms (Trachycarpus fortunei): This palm is native to central and eastern China. The plant may reach 40 feet in height, but it usually ranges from 15-20 feet. A mat of dark brown, hair-like fibers coat the trunk on younger palms. However, older windmill palms tend to lose this mat. The leaves are fan shaped, dark green, and about three feet in diameter. The petiole is about 1 ½ feet long and armed with teeth. The plant is considered monoecious which means that there are male flowers and female flowers on the same plant. The flowers are yellow and the mature blue fruit is three lobed, kidney shaped and approximately ½ inch long. Windmill palms are moderately slow growing and have relatively small crowns, which makes them a good choice for smaller areas. Very popular palm and hardy enough for north LouisianaStateUniversity.
(8)Mediterranean Fan Palm (Chamaerops humilis): The Mediterranean fan palm may reach a height of 20 feet, but usually only grows to 8 feet. The trunk is usually covered with old leaf bases. It may be found in multi-trunked clumps, or it may be found growing solitary. Either way, it is usually low and bushy with stiff, fan-shaped leaves that may be 2-3 feet in diameter. The petiole is slender, long and strongly armed. The Mediterranean fan palm has yellow flowers followed by oval, three sided, ½ to 1 ½ inch long, brown to yellow fruit. Most plants are dioecious, meaning that there are male and female plants. However, some contain both male and female flowers on the same plant. This palm is the only palm native to Europe, and interestingly enough, it is one species of one genus. This slow growing palm is another good candidate for planting in a relatively small area. Mediterranean fan palms are moderately slow growing palms.
(9)Chinese Fan Palm (Livistonia chinensis): This slow growing palm may reach 20-30 feet in height. Often the leaf bases cling to the trunk. The leaves may be 4-6 feet wide, and the segments of the leaves droop downward in a graceful manner. The petioles are armed with yellowish colored teeth which may be more prominent near the base. The teeth seem to disappear with age. These plants are monoecious, meaning that there are male flowers and female flowers on the same plant. The fruit, when mature, may be oblong, ¾ inch long and a dull bluish-green. This is another palm that would be acceptable planted in a relatively small area especially with its graceful appearance. They are moderate in growth rate and will tolerate part shade.
(10)Needle Palm (Rhapidophyllum hystrix): This slow growing palm is native from South Carolina to Florida and west to Mississippi. It is a shrubby palm that may reach a height of 6-8 feet and is found often in heavy clusters. The petioles (leafstalks) are short, with the petiole base covered with dark fibers and long black spines 6-10 inches long extending from the trunk toward the leaves. The leaf is fan shaped and up to four feet in diameter. The inflorescence is short, 6-12 inches long, much branched and buried among the leaf bases and spines. It is tolerant of part shade.
(11)Blue Hesper Palm, Blue Fan Palm (Brahea armata): It is native to lower California and can reach a height of 40 feet in its native habitat. In south Louisiana, a height of 8-10 feet is typical. The petiole may be up to three feet long and armed with strong, curved white teeth. The palmate leaf may span 3-5 feet and is blue-gray in color. They are moderately slow growing palms and scarce in the nursery trade.
(12)Lady Palm (Rhapis excelsa): This palm is native to southern China and may attain a height of 15 feet in its native habitat. In south Louisiana, it scarcely reaches above 4 to 6 feet except in well protected courtyards. It is a multiple trunk species and very slow growing. The leaves are 10-16 inches broad, fan-shaped and dark green in color. The slender trunks are covered with woven fibers and leaf bases. This species is best planted in a location protected from winter winds and in partial shade.
Palm Species with Pinnate (Feather-shaped) Leaves
(13)CanaryIsland Date Palm (Phoenix canariensis): This very large palm may attain a height of 50-60 feet at maturity with a spread of 15 to 20 feet. The Canary Island Date Palm is probably the most tropical and stately of all the palms grown in the New Orleans area. The trunks are very stout when young, up to 4 feet thick; but when older, the trunk becomes smooth, and in some cases, it erodes to possibly less than a foot in diameter. The leaves are pinnate and may be 10 to 15 feet long. This palm is dioecious, meaning that there are male plants and female plants. It is moderately fast growing. The orange globose fruit is about one-inch in diameter and is formed in heavy clusters. This palm is excellent for street planting in any area where it can be allowed to spread to 15 feet and ascend to 50-60 feet.
(14)Date Palm (Phoenix dactylifera): The true date palm has been widely planted across south Louisiana since the early 90s. This stately species is generally planted in large sizes that are field grown and dug. It is not quite as massive as the CanaryIsland date palm, with more slender fronds (which are slightly silver). Large clusters of orange, edible fruit are produced by mature female trees. Large numbers have been planted in downtown New Orleans. The growth rate is faster than P. canariensis.
(15)Senegal Date Palm (Phoenix reclinata): This moderately fast-growing palm is native to tropical Africa. It usually forms a cluster of plants, or if the suckers are removed, the single trunk will usually grow taller than normal. The plant may attain a height of 25 feet, but a mature plant often leans or reclines at an angle. The bright green, slightly recurved leaf is pinnate, and on mature plants the leaves may be 20 feet long. The plant is considered dioecious. The reddish brown fruit is ¾ inch long and somewhat egg shaped. These plants remain somewhat small (less than 10-15 feet in height) in New Orleans because of frequent freezes.
(16)Butia Palm or Jelly Palm (Butia capitata): Butia is native to South America, more specifically Brazil, Paraguay and Argentina. It may attain a height of 20 feet but usually ranges from 10-15 feet here in south Louisiana. The trunks are covered with old leaf bases and may be up to 18 inches thick. The bluish-gray, green leaves are pinnate and recurving, revealing a graceful, arching effect. The petiole is slender with prominent teeth on the margins. The flower stalk may be 4-5 feet long and contain clusters of fruit weighing up to 75 pounds. The individual bright orange fruit may be one-inch long and somewhat ovoid in shape. This fruit may be eaten raw or prepared into jelly. It is relatively slow-growing and somewhat short in growth habit but needs 10-15 feet to spread.
(17)Queen Palm (Syagrus romanzoffiana): The queen palm is native to Central Brazil and Argentina. It may reach a height of 25 feet or taller. The gray trunk may be 1-2 feet in diameter and somewhat smooth but ringed. The plant is particularly attractive and most graceful especially at pool side. The arching green leaves may range from 8-15 feet long with many narrow leaflets. The flowers are cream colored followed by ovoid, yellowish, 1 inch long to 1 ¼ inch wide poisonous fruit. It’s relatively fast growing.
(18)Arenga Palm (Arenga engleri): This less commonly known, hard to find, multi-trunked palm is native to Taiwan. It may reach 6-7 feet tall in a well-protected area such as an enclosed courtyard. This palm has feather-shaped leaves that reach up to 4 feet long. The leaf segments are somewhat undulate or irregularly, but attractively, notched on both sides. It is moderately slow growing.
(19)Bamboo Palm (Chamaedorea microspadix): It is a feather-leaf palm and native to eastern Mexico. This bamboo palm may be easily identified by its orange to red fruit. The multiple trunks may reach up to 6-8 feet tall in New Orleans and look similar to bamboo trunks. Care should be given to plant this palm in a shady to partly shady environment. This species of bamboo palm may be difficult to find in the trade; therefore when purchasing, insist on the botanical name. It is a relatively fast growing, attractive, clumping palm.
Originally Prepared by Severn C. Doughty, Area Agent (Horticulture) (1992)
Revised 2000 by:
Allen D. Owings, Professor (Horticulture)
Robert C. Trawick, County Agent (Horticulture)
Dan Gill, Associate Professor (Horticulture)
Robert Turley, County Agent (Calcasieu-Horticulture)
Revised 2008 by:
Dan Gill, Associate Professor (Consumer Horticulture)
NOTE: Mention of a commercial product or pesticide trade name is done with the understanding that no discrimination is intended and no endorsement is given by the Louisiana Cooperative Extension Service, a branch of the Louisiana State University Agricultural Center.
Louisiana State University Agricultural Center, William B. Richardson, Chancellor
Issued in furtherance of Cooperative Extension work, Acts of Congress of May 8 and June 20, 1914, in cooperation with the United States Department of Agriculture. The Louisiana Cooperative Extension Service provides equal opportunities in programs and employment.