Lychee is a popular tree in Hawaii, valued for its delicious fruit. As its botanical name implies, Litchi chinensis originated in China. Lychee (also written litchi, li-chi) is a large, long-lived, subtropical, evergreen tree that bears fruit from May to August in Hawaii.
The first lychee plant brought to Hawaii was imported from China in 1873 by Mr. Ching Chock and planted on the property of Mr. Chun Afong. It was known as the "Afong" tree and was initially considered to be the Chinese cultivar 'Kwai Mi' (or 'Kwai Mei'), but it was later identified as 'Tai Tso' (or 'Tai So').
Lychee is a round-topped, long-lived, subtropical evergreen tree growing to 40 ft (12 m) in height. Immature leaflets are pale green, often tinged with bronze or pink, turning dark green and leathery when mature. Leaves are pinnate with one to five pairs of leaflets. Flowers are small, greenish-white or yellow, lacking petals, and borne in large numbers on branched, terminal panicles up to 12 inches (30 cm) long. The fruit is a tubercled, oval to ovoid drupe about 1 inch (2.5 cm) in diameter by 11/4 - 11/2 inches (3-4 cm) long with rough, brittle, red skin. The fruit flesh is juicy, white, translucent, and gelatinous, and does not adhere to the seed. The single seed is usually large but occasionally small and shrunken or abortive. Such abortive seeds are often referred to as "chicken tongue" seeds.
In Hawaii, lychee can be grown in almost any type of soil from sea level to 2000 ft (600 m) elevation where annual rainfall is 50–80 inches (1300–2000 mm) or more, or where irrigation is available. Lychee trees require well drained soil and grow best in acidic soil (pH 5.0–5.5).
Hawaii has many microclimates that vary considerably over relatively short distances. Careful site selection can make a great contribution to the growth of lychee trees. Wind protection is critical for good growth and fruit production. An ideal orchard site has long, hot days in summer (82°F, 28°C), adequate rainfall (around 63 inches, 1600 mm), and a cool, dry winter with day/night temperatures of 59/50°F (15/10°C). A dry period between October and February with lower temperatures (<59°F, <15°C) is necessary for prolific flower initiation on mature lychee trees and helps ensure a good crop.
In Hawaii, the cool winter season, generally lasting from October through April, is also the wet season in most places. Winter temperatures vary from year to year.
lychee flowering can be obtained by selecting a dry site with irrigation that can be withheld to create a dry period.
Many lychee varieties are known in various parts of the world, including 26 major and 40 minor varieties identified in Guangdong, China, 33 varieties in India, and numerous local selections in Australia, Florida, Taiwan, Thailand, and Hawaii. Because lychee is one of the most environmentally sensitive fruit trees, improper selection of varieties can result in erratic or no fruit production. Good growth in one location is not a guarantee of similar growth in another. For example, the Chinese variety ‘No Mai Tsz’ is one of the most recognized and preferred lychees in the world, but it is not suitable for production in Hawaii. Two mature ‘No Mai Tsz’ trees at CTAHR’s Waiakea Research Station arboretum (Hilo) produced only two crops during the period 1986–1998.
In Hawaii, good performance is obtained with the varieties ‘Kaimana’ and ‘Groff’, which were selected from ‘Hak Ip’ seedlings by CTAHR horticulturists. They require less chilling for flower initiation than traditional Chinese lychee cultivars. ‘Kaimana’ has proven to be a desirable cultivar because of its early harvest season (May–June), good fruit qualities, and large fruit size. Other lychee varieties that are being grown in Hawaii are ‘Souey Tung’, ‘Hak Ip’, ‘Tai So’, ‘Brewster’, and ‘Bosworth 3’