Publication #ENH-732

Topics: Palm Varieties | Arecaceae (taxonomic family) | Southern Trees Fact Sheets

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

[Click thumbnail to enlarge.]

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

[Click thumbnail to enlarge.]

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

This document is ENH-732, one of a series of the Environmental Horticulture, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date November 1993. Revised December 2006. Reviewed May 2011. Visit the EDIS website at http://edis.ifas.ufl.edu.

Edward F. Gilman, professor, Environmental Horticulture Department; Dennis G. Watson, former 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. Nick T. Place, Dean.

Roystonea spp.: Royal Palm1