Carambola - Cultivation

Cultivation

The carambola is a tropical and subtropical fruit. It can be grown at up to 4,000 feet (1,200 m) in elevation. It prefers full sun exposure, but requires enough humidity and a total of 70 inches or more of rainfall a year. It does not have a soil type preference, but it requires good drainage.

Carambola trees are planted at least 20 feet (6.1 m) from each other and typically are fertilized three times a year. The tree grows rapidly and typically produces fruit at four or five years of age. The large amount of rain during spring actually reduces the amount of fruit, but, in ideal conditions, carambola can produce from 200 to 400 pounds (91 to 180 kg) of fruit a year. The carambola tree flowers throughout the year, with main fruiting seasons from April to June and October to December in Malaysia, for example, but fruiting also occurs at other times in some other locales, such as South Florida.

Major pests are fruit flies, fruit moths, ants, and birds. Crops are also susceptible to frost, especially in the United States and in the Philippines.

Top producers of carambola in the world market include Australia, Guyana, India, Israel, Malaysia, the Philippines, Taiwan, and the United States. Malaysia is a global leader in starfruit production by volume and ships the product widely to Asia and Europe. Due to concerns over pests and pathogens, however, whole starfruits cannot yet be imported to the US from Malaysia under current Food and Drug Administration regulations. In the United States, carambolas are grown in tropical and semitropical areas, including Texas, Florida, Puerto Rico, and Hawaii.

In the United States, commercial cultivation and broad consumer acceptance of the fruit only dates to the 1970s. That acceptance is attributable to Morris Arkin, a backyard horticulturalist, from Coral Gables, Florida. During the late 1960s, Arkin began cultivating plants and trees in his backyard, eventually developing a kind of carambola, or star fruit, that became commercially viable and was named after him. Until the early 1970s, carambola had been grown only as specimen trees in botanical gardens and experiment stations and as a curiosity in home landscapes. However, because of its attractive star shape when cut in cross-section and yellow to golden color, it began to grow in popularity. Fruit from early introductions were however, sour and sometimes considered unpalatable. This limited market and public acceptance, inhibiting development and expansion of carambola as a commercial fresh fruit. Arkin cultivated the 'Arkin' variety – a sweet carambola with good handling characteristics – in the mid to late 1970s. Soon afterward, the limited commercial area of carambola under cultivation in south Florida (4 to 12 ha) was top-worked to 'Arkin' and this new cultivar led to a rapid increase in consumer demand for the fruit which further stimulated interest in establishing new commercial plantings. Today, the 'Arkin' variety represents 98% of the current acreage in South Florida.