Healthy Palms in Healthy

South ‘Florida Landscapes’ JODY L. HAYNES

Introduction twelve Florida-friendly palms; the second section discusses the nine FYN principles as they Palms are widely used throughout Florida as relate to palms in Florida Landscapes; and the dramatic specimen or accent , as avenue third section provides a brief introduction to ‘’, as integral components of raised bed palm-related Internet resources. plantings, as under-story or ‘filler’ plants, and even as living fences or hedges. Although a large proportion of the 2500 palm species will grow ‘Florida-Friendly’ Palms well in south Florida, many of these have relatively high water and fertilizer requirements, A great diversity of palm species is well suited to while others have relatively high pest and disease the subtropical climate of south Florida. Many susceptibilities. have proven to be reliable based on their tolerance of cool winter temperatures, seasonal A smaller number of palms exhibit high drought rainfall, and alkaline soils. However, just tolerance and low fertilizer requirements, and are because a palm will grow in a given region does generally free of pests and diseases. Because of not mean it should be grown there. Numerous their relatively low impact on Florida’s precious palm species have high water and fertilizer and fragile natural environment, this latter group demands, and some are susceptible to pests and can be referred to as ‘Florida friendly’ palms. diseases. Similarly, landscapes in Florida that adhere to the nine principles of the University of Florida’s In south Florida, freshwater is at a premium, and, Florida Yards & Neighborhoods (FYN) program with the latest water restrictions imposed on the are considered to be ‘Florida-friendly’ region by the South Florida Water Management landscapes (i.e., ‘Florida Landscapes’) because District (Phase II restrictions took effect they, too, have a relatively low impact on the Thursday, January 11, 2001; contact the environment. SFWMD for more information), outdoor water use must be reduced to conserve our precious The primary objective of this article is to explore freshwater resources. In addition, large amounts some Florida-friendly palms and how they can of excess nutrients and pesticides that are applied be incorporated into Florida-friendly landscapes. to yards and landscapes in south Florida find The first section below lists and describes the their way into surface waters during flood basic characteristics and culture requirements of events—and eventually into Biscayne Bay—and Healthy Palms & Healthy Landscapes 2 contribute to what is known as non-point source Chambeyronia macrocarpa, the red leaf palm, is pollution. one of the few palms from the low-altitude rainforests of New Caledonia that performs well Not all palms have high fertilizer and water in south Florida’s requirements, or are susceptible to pests and soils and climate. diseases that must be treated with chemical Ultimately reach- pesticides. In 1997, the palm curator at Fairchild ing 20 feet, this Tropical Garden published an updated “Top palm requires well- Ten” list of highly recommended, Florida- drained soil, shade, friendly palms (Maidman, 1997). The following and some supple- list and descriptions are based on this article, mental irrigation with two additional species added. when young, but it can tolerate full Bismarckia nobilis, the Bismarck palm, is a sun and natural native of the savannahs of Madagascar and is an rainfall as it extraordinarily durable and highly adaptable matures. This palm. The impressive silvery-gray, fan-shaped palm’s most im- leaves can reach 6 feet across; therefore, its presssive attribute is its brilliant maroon-red new massive size restricts its use to larger landscapes. leaf, which fades to a dark glossy green within a This palm few days after opening. requires full sun and prefers a fair amount crinita, the old man palm, is a of water when native of . This young, but palm has a performs well characteristic “beard” with no of white-gray fibers. supplemental Although slow irrigation once growing when small, established. its growth rate increases upon Chamaedorea ernesti-augustii is a small, formation of a trunk. solitary, under-story species from the rainforests This is one of the most of through sought-after palms in . The south Florida. sparsely divided to nearly entire leaves are quite attractive, as Cocos nucifera ‘Maypan’ is a coconut hybrid are the raised annular created by hand-pollinating a ‘Malayan Dwarf’ rings on the slender coconut with ‘Panama Tall’ pollen, producing a stem. It grows best in vigorous palm that possesses a fairly high well-drained soil and resistance to Lethal Yellowing disease—a lethal, is atypical of rain- untreatable disease of some coconut varieties and forest palms in that it a few other palm species in south Florida. is fairly drought tolerant. Healthy Palms & Healthy Landscapes 3

young, it becomes quite fast growing once the trunk begins to form. Looking best when planted in small groups, this palm bears a crown of gracefully arching leaves, and the small, white fruits are produced Although the color of the ‘Panama Tall’ parent nearly continuous- generally predominates, the choice of seed parent ly upon matu- also has an effect. Since ‘Malayan Dwarf’ ration. It tolerates cold temperatures if planted in coconuts come in three colors—green, yellow, a sheltered location and can reach 50 feet in and gold/red—the petioles and fruit of the height. ‘Maypan’ hybrid can range from yellowish-green to reddish-bronze. ‘Maypans’ have the classic Pseudophoenix sargentii, the Florida native ‘tall’ trunk and swollen base. Like most buccaneer palm or Sargent’s cherry palm, grows coconuts, they have high drought tolerance, low naturally in sand or nutrient requirements, and few pest problems. limestone soils in areas that receive little baileyana, the Bailey copernicia rainfall. This palm has palm, hales from the dry savannahs and a gray trunk and a woodlands of prominent gray-green Cuba. It prefers crownshaft topped by full sun even as a sparse crown of a seedling and silvery-blue-green has a high leaves. Due to its tolerance of slow-growing habit, drought. Al- this palm is not though slow- common in the nursery growing, hard trade and is often to find, and fairly expensive. However, it is one of the usually a bit hardiest palms for south Florida. expensive, this palm is much Sabal etonia, the scrub palmetto, is a small sought-after in shrub-like palm south Florida whose trunk due to its massive, smooth, slate-gray trunk and usually remains stiff, gray-green ‘fan’ leaves. underground. Its fan-shaped Heterospathe elata, the sagisi palm, is a tall leaves are about rainforest species from the Phillipines and other 3’ across and adjacent islands. Although slow-growing when costapalmate, Healthy Palms & Healthy Landscapes 4 which means that they are essentially palmate a hardy palm with low maintenance except that the petiole (leaf stem) extends part requirements. way through the center of the leaf fan as a midrib. Scrub palmetto resembles saw palmetto, Veitchia species are natives of the South Pacific but the latter has a true palmate leaf with no and are widely midrib. Scrub palm can reach up to 3-4’ tall with planted in south a spread of 4-5’. The flower stalk of scrub Florida. They are palmetto also does not extend beyond the leaves. among the fastest growing palms morrissii, the Keys thatch palm, is and often reach 50 native to the Florida Keys and throughout the feet in height. The and slender trunks, into the Yucatan elegantly arching peninsula, and is leaves, and a relative of the clusters of large, Florida thatch red fruit make palm, T. radiata. these palms This palm grows particularly naturally in alka- attractive when line soils, some- planted in informal groups. Additional appealing times even on attributes include their high toler-ance of limestone out- hurricane-force winds and their wide adapta- crops, and tole- bility to varying soil, water, and nutrient condi- rates drought, tions. Care should be taken to avoid planting low soil fertility, Adonidia merrillii (recently changed from and exposure to salt spray. The leaves of T. Veitchia merrillii; Zona and Fuller, 1999), morrissii are bluish-green above and silver however, as it is highly susceptible to Lethal below. As in most species in the , ripe fruit Yellowing. are white. ‘Florida-Friendly’ Landscapes , the Florida thatch palm, is native to Florida and a few Caribbean islands. It A Florida-friendly landscape is one in which the can reach a right plants are planted in the right places, mulch height of is maximized, water is used efficiently, fertilized 20 feet and is applied appropriately, pests and diseases are grows natu- managed responsibly, yard waste is recycled, rally in wildlife is attracted, and, when located on the sand or on waterfront, special precautions are taken to limestone. reduce non-point source pollution from entering It prefers the water. These landscaping practices represent sun and the nine Florida-friendly principles of the Florida tolerates Yards & Neighborhoods (FYN) program. salty winds. The main difference between this species The FYN program began as a county-level and its close relative, T. morrissii, is that the Extension program in the Tampa Bay and leaves of T. radiata are green on both sides. It is Sarasota Bay areas of Florida—out of the need to Healthy Palms & Healthy Landscapes 5 address serious problems of pollution and and sandy soils of south Florida. Mulch should disappearing habitats. FYN has since been be applied 3-4 inches thick around all palms and adopted and promoted by the University of should be reapplied as needed—which is usually Florida Extension as a statewide program. The on a semiannual or annual basis. Although mulch FYN program objectives are based on the above is a good starter material, it may not always be a nine Florida-friendly landscaping principles that final landscape feature. Groundcovers serve a homeowners, landscape designers, and landscape similar function, in that they shade the ground, maintenance personnel can utilize to create and control weeds, and add organic matter to the soil, maintain Florida-friendly landscapes. In this while also adding texture and/or color to the section, these nine principles will be discussed as landscape. Numerous drought-tolerant they relate to the placement and maintenance of groundcover species are available for use in palms in Florida Landscapes. Florida Landscapes.

Right , Right Place—Learning the specific Water Efficiently—According to the South culture requirements and site preferences for Florida Water Management District, about 50% each palm species of interest is the first step in of south Florida’s average annual water creating a Florida Landscape. Betrock’s Guide to consumption is used for lawn and landscape Landscape Palms (Meerow, 1994) provides irrigation and other outdoor activities. With general culture information on 10 of the 12 respect to palms, over-watering greatly increases recommended Florida-friendly palms discussed the likelihood of root rot. Conversely, watering above. Numerous other books and websites are infrequently and for a longer duration induces available for additional information (see below). deeper growth of palm roots, thereby increasing their drought tolerance. Although many The second step is to conduct a thorough site rainforest palms can be grown in south Florida, evaluation of the landscape. Important aspects of most are not recommended for Florida site evaluation include sun and shade patterns; Landscapes due to their high water requirements. soil type and pH; location of existing structures, power lines, and water lines; location of existing Fertilize Appropriately— Palms are particularly plants; and location of areas where water stands susceptible to micronutrient deficiencies in south or runs off. Florida due to the poor nature of the soils. Deficiencies can even occur when palms receive The final step in this principle is to choose palm regular fertilizer applications because most species whose requirements correspond to the fertilizers do not contain the proper complement respective site conditions, keeping in mind that it of micronutrients that palms require. Therefore, is best to group plants with similar requirements proper fertilization practices are crucial in in the same area. Common problem spots that maintaining healthy palms. should be avoided include under power lines, too close to buildings, and in low-lying areas where Broschat (1998) recently provided revised water collects during heavy rains. recommendations for palm fertilization (see also Broschat & Meerow, 1999): Maximize Mulch & Groundcover—The benefits of mulch are numerous and include conserving Palms and other landscape ornamentals can be … water, moderating soil temperature, discouraging effectively and efficiently fertilized by broad- casting a 2N-1P-3K-1Mg plus micronutrients weeds, and preventing damage from mowers and fertilizer over the entire ornamental landscape line trimmers. Organic mulches have an added area at a rate of 1.5 lbs/100 sq. ft. every 3 months. benefit, in that they help improve the limestone These fertilizers should have 100% of their N, K, and Mg in controlled release form to maximize Healthy Palms & Healthy Landscapes 6

their effectiveness to the plants and minimize waste generated in Miami-Dade County (pers. their impact on the environment. comm., Irving Gerson, Miami-Dade Solid Waste Management). A significant proportion of this The benefit of these recommendations for yard waste consisted of pruned (over-pruned?) Florida Landscapes (and for Florida’s natural palm fronds. Ironically, palms do not need to be environment as well) is the use of slow release, pruned; in fact, the health of palms is low phosphorus fertilizers at a rate that is just significantly threatened by over-pruning. sufficient for healthy palm growth. Furthermore, due to the nearly ubiquitous

problems with micronutrient deficiencies in Manage or Prevent Diseases & Pests—Palm palms in south Florida, pruning green or healthy diseases can be broadly categorized as those that fronds eliminates a primary source of these are untreatable and are always fatal, those that micronutrients, since palms recycle many are sometimes fatal but are treatable, and those nutrients from old to new leaves. Therefore, that are simply cosmetic. The most important of palm fronds should only be cut off (if at all) these with respect to palms in south Florida when they are brown and dry. Then, the dead Landscapes are those that are sometimes fatal but fronds should be shredded or composted, thereby are generally easily treatable. Such diseases greatly reducing the amount of organic debris include phytophthora root, crown, and trunk rots, added to landfills and providing a sustainable bacterial bud rot, pink rot, and damping off. source of mulch or compost. Converting palm Although complete prevention of these diseases leaf debris to compost has the added benefit of is not possible, proper maintenance schedules, quickly recycling nutrients back into the soil, proper planting depth, proper placement in the thereby reducing the need for inorganic landscape, and mulching all help to reduce fertilizers. disease incidence. If disease is suspected, contact your local Extension office for Florida-friendly Attract Wildlife—Palms are not generally known treatment recommendations. for their attractiveness to wildlife, although there

are some notable exceptions. For example, the Although healthy, well-grown palms will native sabal palm (Sabal palmetto, which is typically be relatively free of debilitating insect Florida’s State ‘’) attracts birds, which feed pests (Meerow, 1994), pests do sometimes attack on the fruits. Another native palm, the saw landscape palms in sufficient force to cause palmetto (Serenoa repens), is utilized by various concern—particularly when palms are weakened wildlife species for nesting, protective cover, and by improper fertilization or excessive watering. as a food source. Both of these species, although Insects that can cause significant pest problems not listed above, are recommended palms for include scale insects, palm aphids, spider mites, Florida Landscapes. coconut mites, banana moths, palm leaf skeletonizers, royal palm bugs, palmetto weevils, Protect the Waterfront—Only a few palms various caterpillars, and some grasshoppers prefer to grow near water. One example is the (Meerow, 1994). Most of these pests can be paurotis or Everglades palm (Acoelorrhaphe successfully treated with oils, soaps, bio-control wrightii), which prefers to have its “feet wet” at products, or natural predators, but the most all times and performs best when the soil is efficient ‘pre’-solution to this problem is to constantly saturated. Other species, such as the choose palms that are resistant to common pests mangrove palm (Nypa fruticans) and the and diseases (see list above), and then make sure mangrove (Licuala spinosa), actually they are properly maintained. prefer to live along or in brackish waters. Unless Recycle Yard Waste—In 1999, yard waste made planted near water, these palms are generally not up 14% of the 3.6 million tons of municipal solid Healthy Palms & Healthy Landscapes 7 recommended for Florida Landscapes due to names; a glossary and pronunciation guide their high water requirements. One Florida- containing over 1000 palm genus and species friendly landscape practice that does not involve names; a cross-reference containing over 300 palms but that can help reduce excess nutrients palm common and botanical names; and links to and pesticides from running off into water bodies numerous other palm-related Internet resources. from adjacent landscapes is to establish a 20-foot “No-Application Zone” along the entirety of the Literature Cited waterfront. Since no fertilizers or pesticides are applied in this zone, non-point source pollution Broschat, T. K. 1998. Why aren’t your palms green? can be reduced. Tropicline 10. (Online at http://www.ftld.ufl.edu/Volume%2010(1).ht Reduce Non-Point Source Pollution—Adhering ml#GreenPalm.) to the previous eight principles will greatly reduce non-point source pollution originating Broschat, T. K., and A. W. Meerow. 1999. Palm Nutrition Guide. Updated Fact Sheet SS- from Florida Landscapes. The best course of ORH-02, Institute of Food and Agricultural action with respect to palms is to plant species Sciences, University of Florida Extension. that have low fertilizer and water requirements (Online at http://edis.ifas.ufl.edu/EP052.) and few pests and diseases (see list above). Maidman, K. 1997. Ten great palms. Garden News Palm Internet Resources (Newsletter of Fairchild Tropical Garden) 52(5):10-11. The past few years have witnessed a virtual explosion of palm-related information on the Meerow, A. W. 1994. Betrock’s Guide to Landscape Internet. Interested persons can now subscribe to Palms. Betrock Information Systems, Hollywood, FL. e-mail lists about palms, participate in online discussion forums, and visit numerous websites Meerow, A. W., and T. J. Weissling. 1998. Pests of throughout the world that contain information on Palms in Florida and the Caribbean Region. palms. Online presentation, University of Florida, Ft. Lauderdale Research & Education Center. One of the most comprehensive online palm URL: http://www.ftld.ufl.edu/Palm%20 resources is the website of the Palm & Cycad Insects-WEB-no%20animation/index.htm. Societies of Florida, Inc., located at the following URL: www.plantapalm.com. This Zona, S., and D. Fuller. 1999. A revision of Veitchia website is the home of the Virtual Palm (—Arecoideae). Harvard Papers in Botany 4:543-560. Encyclopedia (VPE). Here you will find over 50 articles on palms, ranging from general palm horticulture to conservation, ethnobotany, , evolution, and pests and diseases.

Also included in the VPE are over 1200 photos of over 500 palm species; a graphical key to common landscape palms; information on cold- hardiness in palms, including several hardiness zone maps; a PowerPoint presentation on palm pests in Florida; University of Florida palm fact sheets; a compiled list of over 1700 palm species