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Publication #ENH445

Guaiacum sanctum: Lignumvitae1

Edward F. Gilman and Dennis G. Watson2

Introduction

Lignumvitae is an extremely slow-growing broadleaf evergreen which ultimately reaches 30 to 40 feet in height and casts light shade, but few people have seen plants of this size because it is not grown in the trade. Most are seen 8 to 12 feet tall with a beautiful array of multiple trunks and a rounded canopy much like that of a mature Crape-Myrtle. The one to two-inch-long, leathery, dark green leaves are joined at many times throughout the year by the production of large clusters of deep blue flowers, the old flowers fading to a light silvery-blue and creating a shimmering haze over the rounded canopy. These flowers are followed by small, heart-shaped, yellow berries, appearing on the tree at the same time as the blue flowers and creating a lovely sight.

Figure 1. 

Mature Guaiacum sanctum: Lignumvitae

General Information

Scientific name: Guaiacum sanctum
Pronunciation: GWY-uh-kum SANK-tum
Common name(s): Lignumvitae
Family: Zygophyllaceae
USDA hardiness zones: 10B through 11 (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: tree lawn 3-4 feet wide; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; sidewalk cutout (tree pit); parking lot island < 100 sq ft; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; container or planter; specimen; deck or patio; Bonsai; highway median
Availability: not native to North America

Figure 2. 

Range

Description

Height: 8 to 12 feet
Spread: 8 to 12 feet
Crown uniformity: symmetrical
Crown shape: round, vase
Crown density: dense
Growth rate: slow
Texture: fine

Foliage

Leaf arrangement: opposite/subopposite (Fig. 3)
Leaf type: even-pinnately compound
Leaf margin: entire
Leaf shape: obovate, elliptic (oval)
Leaf venation: pinnate
Leaf type and persistence: evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy

Flower

Flower color: blue
Flower characteristics: very showy

Fruit

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

Trunk and Branches

Trunk/bark/branches: branches droop; very showy; typically multi-trunked; thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: gray
Current year twig thickness: thin
Wood specific gravity: 1.09

Culture

Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; alkaline; acidic; extended flooding; well-drained
Drought tolerance: high
Aerosol salt tolerance: high

Other

Roots: not a problem
Winter interest: yes
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: free of serious pests and diseases

Figure 3. 

Foliage

Use and Management

Underneath the smooth, beige/grey bark of Lignumvitae is some of the heaviest of all wood, sinking under its weight instead of floating in water. This dense wood was once popular for use in the manufacture of bowling balls and has also been used for propeller shafts on steamships, gears and for mallets. The picturesque crooked, typically multiple trunk, evergreen leaves, and beautiful flowers, and fruit would all combine to make Lignumvitae a popular choice for use as a container, patio, or specimen planting if it were widely available in a range of sizes. Unfortunately, like many other slow-growing trees, this one is not often grown in nurseries. One must travel to arboreta to view nice specimens of this tree.

Lignumvitae can be grown in full sun or partial shade on a wide variety of soils, including alkaline. Plants will easily tolerate wet or dry soil, wind, and salt, making it an ideal choice especially for seaside plantings.

Guaiacum officinale grows 10 to 30 feet tall, has blue or sometimes white flowers, and light to dark brown seeds.

Propagation is by seed.

Pests and Diseases

No pests or diseases of concern.

Footnotes

1.

This document is ENH445, 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.