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Publication #ENH-732

Roystonea spp.: Royal Palm1

Edward F. Gilman and Dennis G. Watson2

Introduction

Notably popular as street or specimen trees, Royal Palms make a neat, tidy, yet stately landscape element for large landscapes, often reaching 50 to 100 feet in height in almost as many years. The tall, smooth, cement grey trunks are capped with a glossy, green crown shaft several feet high and a beautiful, broad, dense crown of soft, gently drooping, feathery fronds. Flowers are incredibly fragrant, even from 50 feet away and are produced periodically throughout the year but mostly in summer. The old fronds should be removed before they drop since they can cause injury or damage to plants or property when allowed to fall. One frond will fall about every month.

Figure 1. 

Mature Roystonea spp.: Royal Palm

General Information

Scientific name: Roystonea spp.
Pronunciation: roy-STOW-nee-uh species
Common name(s): Royal Palm
Family: Arecaceae
USDA hardiness zones: 10A through 11 (Fig. 2)
Origin: native to North America
Invasive potential: little invasive potential
Uses: street without sidewalk; specimen; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; sidewalk cutout (tree pit); tree lawn 3-4 feet wide; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; urban tolerant; highway median
Availability: not native to North America

Figure 2. 

Range

Description

Height: 50 to 80 feet
Spread: 15 to 25 feet
Crown uniformity: symmetrical
Crown shape: palm, upright/erect
Crown density: open
Growth rate: moderate
Texture: coarse

Foliage

Leaf arrangement: alternate (Fig. 3)
Leaf type: odd-pinnately compound
Leaf margin: entire
Leaf shape: lanceolate
Leaf venation: parallel
Leaf type and persistence: evergreen
Leaf blade length: 18 to 36 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy

Flower

Flower color: yellow
Flower characteristics: showy

Fruit

Fruit shape: oval, round
Fruit length: less than .5 inch
Fruit covering: fleshy
Fruit color: purple, black
Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically one trunk; thorns
Pruning requirement: little required
Breakage: resistant
Current year twig color: not applicable
Current year twig thickness:
Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; acidic; slightly alkaline; occasionally wet; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: moderate

Other

Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

Royal Palms grow quite rapidly when given an abundance of water and fertilizer in full sun or dappled shade. They withstand strong winds and salt spray very well but some foliage injury will be evident on Royal Palm located next to the ocean. It is not really suited for beach side planting as Sabal Palm is. The young developing fronds grow in a distorted, frizzled manner in alkaline soil. This is usually attributed to manganese or iron deficiency in the leaves. It can be prevented with regular applications of a suitable fertilizer or by planting in soil with a pH less than about 7.5.

Roystonea elata is native to Florida and Roystonea regia to Cuba. Cuban Royal Palm has less prominent secondary leaf veins and nearly globose fruit. Many nurseries do not distinguish between these two species since they are very similar.

Propagation is by seed.

Pests

Some of Royal Palm's pests are palm leaf skeletonizer, Royal Palm bug, giant palm weevil, and scales when young. Any of these can be troublesome in localized areas.

Diseases

Ganoderma butt rot is the most serious problem on Royal Palms. It kills trees which it infects. The disease often enters the trunk through injuries on the lower trunk and roots.

Footnotes

1.

This document is ENH-732, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date November 1993. Revised December 2006. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.

2.

Edward F. Gilman, professor, Environmental Horticulture Department; Dennis G. Watson, associate professor, Agricultural Engineering Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.