Sour orange is an evergreen tree in the Rutaceae family that grows up to 30 feet tall in a tropical, sub-tropical habitat. The fruit is inedible as it is very bitter but is essential in making marmalades and liquors such as Triple Sec. It is native to southeastern Asia and has been carried and cultivated throughout the tropical regions of the world. Its name comes from the Latin noun aurantium, meaning "of orange." It has smooth, brown bark with thorns. In cooler zones it can be grown in a container that can be overwintered indoors. Plant sour orange in full sun, with moist but not overly wet soil. Water regularly, allowing the soil time to dry out between watering. It does well in medium (loamy) and heavy (clay) soils with a pH of 5 - 8 but it can grow in very alkaline soils also. Care should be taken in its location as it is moderately frost-tender but can survive short freezes. It must get early morning sunlight during the growing season, which is in late winter and early spring, so new, tender branches don't freeze. The tree propagates readily from seed. The sour orange became more widely grown as a rootstock for other citrus varieties than for its fruit because of its disease resistance and greater hardiness. But the tree still provides many medicinal benefits and commercial uses for the fruit, flowers, and peel. Plant outside for year-round enjoyment in the proper hardiness zone or put in a planter for movement inside when the weather turns cold. Sour orange dislikes root disturbance so it should be placed in its permanent location outside when young. If growing them in pots, great care must be taken when moving them to larger containers. Insects, Diseases and Other Plant Problems: Anthracnose is sometimes seen. Overwatering may cause fungal infections or root rot and the tree to decline in fruit production. The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common citrus insect and related pests.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Fills a similar nicheCitrus x aurantiifoliaCitrus x limonCitrus x sinensis
Full plant profile
Growing Conditions
Plant type
Edible; Houseplant; Tree
Life cycle
Woody
USDA zones
8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
Light
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Clay; Loam (Silt)
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Available space
12-24 feet
Mature size
Height: 5 ft. 0 in. - 30 ft. 0 in. | Width: 16 ft. 0 in. - 20 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
2 - Understory (15-40 ft)
Form & Appearance
Habit / form
Rounded; Spreading
Texture
Medium
Foliage
Broadleaf Evergreen
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Alternate
Leaf shape
Elliptical; Ovate
Leaf margin
Crenulate; Entire
Leaf feel
Glossy
Leaf value
Fragrant
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
No
Leaf detail
Evergreen leaves are very fragrant, usually ovate, 2 1/2 to 5 1/2 inches long and 1 1/2 to 4 inches wide, minutely toothed, dark green in color above, pale beneath.
Flower color
White
Flower value
Fragrant; Showy
Flower form
Raceme
Flower shape
Star
Flower size
1-3 inches
Flower detail
Large white fragrant flowers about 1 1/2 inches wide singly or in small clusters with 5 white petals that look like a star surrounding a tuft of up to 24 yellow stamens.
Bloom time
Spring
Fruit color
Green; Orange; Red/Burgundy
Fruit type
Berry
Fruit value
Fragrant
Fruit size
1-3 inches long, > 3 inches wide
Fruit detail
The fruit is round, with an aromatic, thick peel, rough-surfaced, fragrant, becoming bright reddish-orange on maturity. The pulp is very sour and bitter.
Bark color
Dark Brown
Bark detail
Smooth, brown bark with thorns from 1 in to 3 1/8 in long.
Stem color
Green
Stem detail
New year's growth is green in color.
Wildlife & Ecology
Native status
Non-native
Origin
Southeastern Asia
Distribution
Tropical and sub-tropical regions of the world, including Fiji, Samoa, Guam, middle east, India, Africa, Italy, Spain, England, the Caribbean, Bermuda, the Americas, Florida
Attracts
Bees
Play value
Attractive Flowers; Fragrance
Food & Medicine
Harvest time
Fall; Summer
Fruit type
Berry
Edibility
Fruit is very bitter and sour. The rind is boiled down with sugar to make marmalade.
Uses (ethnobotany)
The juice, peel, and essential oil (Neroli) in flowers have all been used in skin care products because of its antibacterial, antifungal, antiseptic, and anti-inflammatory properties. Sour orange is also used in perfume and hair care products to provide a fragrance of citrus.
Landscape Use
Landscape location
Container; Lawn; Meadow
Landscape theme
Edible Garden
Design feature
Flowering Tree; Shade Tree
Garden tags
#interiorscape #showy flowers #evergreen tree #white flowers #fragrant flowers #problem for cats #problem for dogs #problem for horses #tropical feel #container plant #frost tender #orange fruits #fragrant leaves #full sun #thorns #glossy leaves #showy #medicinal #alkaline soils tolerant #fruit tree #citrus fragrance #evergreen
Problems & Resistance
Problems
Problem for Cats; Problem for Dogs; Problem for Horses; Spines/Thorns