Citrus × microcarpa
Common Name: calamondin 
Type: Broadleaf evergreen
Family: Rutaceae
Zone: 10 to 11
Height: 10.00 to 20.00 feet
Spread: 6.00 to 10.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Hedge, Flowering Tree
Flower: Showy, Fragrant
Leaf: Fragrant, Evergreen
Fruit: Showy, Edible
Other: Winter Interest

Culture

Winter hardy to USDA Zones 10-11 where it is best grown in organically rich, well-drained, sandy or clay loams in full sun. Tolerates part shade, but best flowering occurs in full sun. Best with consistent and regular watering. Established trees have moderate drought tolerance. Avoid wet poorly drained soils. Plants will struggle with temperatures below 40°F., and are intolerant of frost. North of USDA Zone 10, calamondin is best grown in a container which is overwintered indoors. Use a loose, all-purpose, well-drained potting mix. Set containers outdoors in late spring in full sun in a location protected from wind. Bring containers indoors in fall for overwintering to a cool but bright sunny southern window. In winter, mist plants with water or use a humidifier to increase the ambient humidity around the plant. Propagate by seed or cuttings.

Noteworthy Characteristics

Citrus × microcarpa, commonly known as calamondin or orange calamondin, is a small, bushy, evergreen tree or shrub which probably originates from China or the Philippines. It is believed to be a cross between Citrus reticulata (mandarin) and Fortunella japonica (kumquat). It is commercially grown in the Philippines, tropical Asia and parts of Latin America where the edible fruit is commonly consumed as a food. In the United States it is more commonly grown as an ornamental. Mature plants will reach up to 6-20' tall (smaller when grown in containers as houseplants). It produces a thin-skinned, juicy, golf-ball sized orange fruit (1 1/2" diameter) which is edible but the pulp and juice are very acidic (sour). The peel is sweet. Fruit remains on the plant for a long time (takes up to one year for fruit to ripen to orange). Each fruit contains 6-9 fleshy segments. Fragrant, white, 5-petaled flowers bloom primarily in spring, but basically may produce 4-5 smaller flushes throughout the year. Seeing flowers and ripe fruit on the plant at the same time is not unusual. Branches (sometimes with small number of short spines) are clad with oval, rich, slightly glossy, evergreen green leaves (to 2-4" long). Leaves are aromatic.

The genus name Citrus is from classical Latin.

The specific epithet microcarpa means "small fruit" in reference to the relatively small size of the fruit of this hybrid.

Problems

Susceptible to Mediterranean and Caribbean fruit flies (Florida problem in particular). Aphids, spider mites, mealybugs, scale and citrus bark borers. Potential diseases include leaf mottling and citrus canker. Container grown plants brought indoors for winter may experience leaf drop.

Uses

Outdoors it is ornamentally attractive around homes or patios. May be grown as a hedge. Indoors, it serves as an excellent houseplant featuring fragrant white flowers and small orange fruits. Fruit is very sour but has a large number of culinary uses including juice added to beverages, food flavoring, sauces, marmalades, pies, and soups.