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Publication #ENH328

Citrus spp.: Citrus1

Edward F. Gilman and Dennis G. Watson2

Introduction

The dense, rounded crown of dark green, evergreen foliage and the pure white, extremely fragrant blossoms make citrus a popular garden choice for frost-free locations. Ranging from 12 to 30 feet in height and 8 to 25 feet in width, depending upon species and cultivar, citrus can be used for shade, to screen unwanted views, or smaller varieties can be used in containers. The juicy, fragrant fruits vary from yellow, orange, or red, and are most noticeable in winter.

Figure 1. 

Young Citrus spp.: Citrus

General Information

Scientific name: Citrus spp.
Pronunciation: SIH-trus species
Common name(s): Citrus
Family: Rutaceae
USDA hardiness zones: 9A 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: hedge; urban tolerant; deck or patio; screen; fruit; specimen; espalier; highway median; trained as a standard
Availability: not native to North America

Figure 2. 

Range

Description

Height: 12 to 30 feet
Spread: 15 to 25 feet
Crown uniformity: symmetrical
Crown shape: round
Crown density: dense
Growth rate: moderate
Texture: medium

Foliage

Leaf arrangement: alternate (Fig. 3)
Leaf type: trifoliate, simple
Leaf margin: serrulate, crenate
Leaf shape: ovate, obovate
Leaf venation: pinnate
Leaf type and persistence: evergreen, broadleaf evergreen
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy

Flower

Flower color: white/cream/gray
Flower characteristics: showy

Fruit

Fruit shape: round
Fruit length: 1 to 3 inches, 3 to 6 inches
Fruit covering: fleshy
Fruit color: orange, yellow, green
Fruit characteristics: attracts squirrels/mammals; showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; not showy; typically multi-trunked; no thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: green
Current year twig thickness: medium
Wood specific gravity: unknown

Culture

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

Other

Roots: not a problem
Winter interest: yes
Outstanding tree: no
Ozone sensitivity: unknown
Verticillium wilt susceptibility: resistant
Pest resistance: sensitive to pests/diseases

Figure 3. 

Foliage

Use and Management

The green, thorny branches will rarely need pruning after a strong branch structure is developed. Prune so there is no bark embedded or pinched together in the branch crotches. This condition could cause the branch to break from the trunk when fruit loads it down. Prune out enough of the foliage on lateral branches so they remain less than half the diameter of the trunk.

Citrus should be grown in full sun on well-drained, slightly acid soil, and watered faithfully. Do not mulch the soil beneath citrus. It is very heat-tolerant and can be effectively used in a tough urban site such as a parking lot if dropping fruits will not pose a problem.

Many species of citrus are available. Citrus limon gives us lemons; Citrus reticulata , tangerines or Mandarin oranges; Citrus sinensis , sweet orange; Citrus aurantifolia , key limes; and Citrus paradisi , grapefruit.

Propagation is by grafting or layering.

Pests

Nematodes, scales, whiteflies, mites, caterpillars, fruitfly.

Diseases

Virus and fungus diseases. Twig galls sometimes form in response to a fungus infection.

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/

Footnotes

1.

This document is ENH328, 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 March 2007. Reviewed October 2003. 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.