The longan fruit tree, also known as lungan and dragon eye, made its debut in the United States in 1903. By the 1990s, the tree started appearing in commercial fields. The tree also grows in gardens and landscapes in warm climates. The tree represents an important crop in southeast Asia, with increasing importance in Florida.
Longan fruit trees grow in subtropical landscapes in China, Thailand, India, Australia, Kenya and several Central and South American countries. The fruit also grows in the United States in California, Florida and Hawaii, where temperatures rarely drop below freezing.
Between 30 and 40 varieties of the longan fruit tree grow commercially around the world. In Florida, the most commonly planted longan is the Kohala. Another cultivar is Diamond River, grown primarily in Thailand. While the fruit quality is only fair, the tree bears fruit every year and also produces fruit off-season with a large, late-season crop.
This evergreen tree features dark green, leathery leaves densely packed on the tree. The leaves grow up to 12 inches in length with blunt pointed tips. Each leaf contains six to nine pairs of leaflets. The longan grows up to 100 feet in height in ideal conditions, although in the United States, the tree typically reaches 40 feet in height and width. The small flowers with five to six sepals and petals appear brownish to greenish-yellow in color. In the United States, the flowers usually begin blooming from February to the beginning of May. After the flowers fade, anywhere from a few to 350 fruits start to grow on each branch.
The small fruits appear either round or oval in shape, growing up to almost 1.5 inches in size. Each fruit weighs from one quarter to a half ounce. The fruits feature tan or brown peels with leathery and smooth skin. Inside the fruit, the pulp looks white and translucent. Each fruit contains one brown seed, with the seed easily removed from the pulp. The pulp tastes sweet. The fruits mature in 140 to 190 days from flowering.
Longans grow in areas with distinctive rainy and dry periods and either mild or cool, nonfreezing winters. The trees grow best in warm temperatures between 70 and 85 degrees Fahrenheit during the spring and 80 to 95 degree in the summer, with plenty of rain. The trees grow best when minimal amounts of rain fall during flowering; otherwise the flowers prematurely drop off the branches, limiting pollination and setting of the fruit. The trees thrive in full sun in almost any type of soil, including sandy loams and sand, as long as it drains well.