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Citrus × aurantium

orange

Rutaceae

Hybrid of cultivated origin; ancestors from Southeast Asia

Attracts Pollinators Attracts Butterflies Fragrant (strong)Container Friendly

SunFull Sun

WaterMedium

HardinessZones 9–11

Overview

Citrus x aurantium is an evergreen tree or large shrub reaching 15-30 feet (4.5-9 m) tall and 10-20 feet (3-6 m) wide, with a dense, rounded crown and often spiny branches. The glossy dark green leaves are oval, 3-4 inches (8-10 cm) long, with broadly winged leaf stalks, and release a citrus scent when crushed. White, five-petaled flowers about 1 inch (2.5 cm) across are strongly fragrant and open in late winter and spring, singly or in small clusters. Round fruit 2.5-3 inches (6-8 cm) wide ripens orange with a thick, rough rind and sour, seedy pulp over fall and winter. This hybrid of Citrus maxima and Citrus reticulata is grown for its fruit, fragrant flowers, and use as a grafting rootstock. The tree is damaged below about 25 F (-4 C) and grows only in mild, frost-free regions. Dropped fruit and leaves create litter under the canopy.

Native Range

A hybrid of cultivated origin, derived from crosses of the pomelo, Citrus maxima, and the mandarin, Citrus reticulata, whose wild ancestors come from Southeast Asia and southern China. Long grown around the Mediterranean, the Americas, and other warm regions, it is not part of any natural wild flora.

Suggested Uses

Grown for sour fruit used in marmalade and flavorings, for fragrant flowers used in perfume and neroli oil, and as a grafting rootstock for other citrus, spaced 12-20 feet (3.5-6 m) apart. Planted as an evergreen specimen or clipped hedge in frost-free gardens and grown in containers elsewhere. Cold sensitivity restricts in-ground use to mild regions.

How to Identify

Recognized by glossy oval leaves with broadly winged leaf stalks, fragrant white five-petaled flowers, and round orange fruit 2.5-3 inches (6-8 cm) wide with a thick, rough rind and sour pulp. The winged petioles and sour fruit separate it from the sweet orange, Citrus x sinensis, which has narrowly winged petioles and sweet pulp.

Appearance

Size & Dimensions

Height15' - 30'

Width/Spread10' - 20'

Reaches mature size in approximately 6 years

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~5 weeks

Winter Spring

Fragrant white flowers open mainly in late winter and spring, with scattered flowering at other times in mild climates. The main flush lasts 3-5 weeks. Fruit set follows, and the fruit ripens slowly through the following fall and winter.

Detailed Descriptions

Foliage Description

Glossy dark green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam sand clay

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

3-6 years

Care & Maintenance

Care Guide

Grow in full sun in deep, well-drained soil; the tree tolerates a range of soils but not standing water. Water deeply and regularly during dry spells, letting the top few inches dry between waterings, since soggy soil causes root rot. Feed with a citrus fertilizer during the growing season. Temperatures below about 25 F (-4 C) damage leaves and fruit, so the tree grows outdoors only in frost-free regions and is otherwise kept in containers and moved under cover. Scale, aphids, citrus leaf miner, and root rot are the main problems.

Pruning

Prune in late winter or after harvest to take out dead, crossing, or crowded branches and to shape the canopy. Remove suckers and any shoots arising below the graft union as they appear. Light annual thinning improves air flow and light within the crown.

Pruning Schedule

winter