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Publication #ENH590

Parkinsonia aculeata: Jerusalem-Thorn1

Edward F. Gilman and Dennis G. Watson2

Introduction

Loose, flowing, delicate leaflets, a light, airy, low-branching growth habit with pendulous branch-tips, and a profusion of small, slightly fragrant, yellow blooms combine to create this popular, small landscape tree. Quickly reaching a height of 20 to 25 feet with a similar spread, this multitrunked deciduous tree is actually much stronger than its fragile appearance would suggest. Branch bark often remains bright green even on several-year-old limbs.

Figure 1. 

Middle-aged Parkinsonia aculeata: Jerusalem-Thorn


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General Information

Scientific name: Parkinsonia aculeata
Pronunciation: par-kin-SO-nee-uh ah-kew-lee-AY-tuh
Common name(s): Jerusalem-Thorn, Retama
Family: Leguminosae
USDA hardiness zones: 8B through 11 (Fig. 2)
Origin: not native to North America
Invasive potential: has been evaluated using the IFAS Assessment of the Status of Non-Native Plants in Florida's Natural Areas (Fox et al. 2005). This species is not documented in any undisturbed natural areas in Florida. Thus, it is not considered a problem species and may be used in Florida.
Uses: street without sidewalk; specimen; parking lot island < 100 sq ft; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; urban tolerant; highway median
Availability: not native to North America

Figure 2. 

Range


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Description

Height: 15 to 20 feet
Spread: 20 to 25 feet
Crown uniformity: irregular
Crown shape: vase, spreading
Crown density: open
Growth rate: fast
Texture: fine

Foliage

Leaf arrangement: alternate (Fig. 3)
Leaf type: odd-pinnately compound
Leaf margin: entire
Leaf shape: linear, oblanceolate
Leaf venation: none, or difficult to see
Leaf type and persistence: deciduous
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy

Flower

Flower color: yellow
Flower characteristics: very showy

Fruit

Fruit shape: pod or pod-like
Fruit length: 1 to 3 inches, 3 to 6 inches
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; showy; typically multi-trunked; no thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: green
Current year twig thickness: thin, medium
Wood specific gravity: unknown

Culture

Light requirement: full sun
Soil tolerances: clay; sand; loam; alkaline; acidic; well-drained
Drought tolerance: high
Aerosol salt tolerance: high

Other

Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: free of serious pests and diseases

Figure 3. 

Foliage


[Click thumbnail to enlarge.]

Use and Management

Be sure to purchase trees with a well-developed central leader and upright branches for street and parking lot plantings to allow for clearance for vehicles. This can be a tough chore as branches weep toward the ground as they spread from the tree so older specimens can be wider than tall. Open-grown trees are beautiful if left unpruned, forming a fountain of fine texture. The stems are armed with short, sharp spines and the trees should be located where they will not injure passersby.

Thriving in full sun on any well-drained soil, Jerusalem-Thorn will tolerate heat, drought, alkaline soil, and salt but not wet, soggy soil. It will grow in clay only if it drains very well. In spite of its rapid growth rate, it has strong wood, withstanding harsh winds with ease due to the open growth habit. However, the trees have a short life, approximately 15 to 20 years. Poor drainage may account for short life on many sites, so locate it accordingly in areas where soil is never wet for more than an hour or two. The bark is thin and easily injured and the tree appears to compartmentalize decay poorly. Locate the tree properly and design the site to minimize trunk injury.

Adapted to arid regions, Jerusalem-Thorn is one of the best choices for hot, dry locations and its salt-tolerance makes it ideal for seaside plantings. The light shade afforded by the fine-textured foliage allows lawns to thrive beneath this tree and its small size allows a multitude of applications, from specimen, parking lot, median, or street tree, set back from the road or walk. There are reports of the plant escaping cultivation in some locations along the gulf coast.

Propagation is by seed.

Pests

Some pests of Jerusalen Thorn are scales and thorn bugs, but none are serious.

Diseases

One disease that infects this tree on wet soils is root rot but none are serious on other sites.

Witches-broom occasionally causes a proliferation of branches forming tight heads of foliage.

Literature Cited

Fox, A.M., D.R. Gordon, J.A. Dusky, L. Tyson, and R.K. Stocker (2005) IFAS Assessment of the Status of Non-Native Plants in Florida's Natural Areas. Cited from the Internet (November 3, 2006), http://plants.ifas.ufl.edu/assessment.html

Footnotes

1.

This document is ENH590, 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 March 2007. Reviewed May 2011. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

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 UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.