At the Fullerton Arboretum

By Alfredo Chiri

 LONGAN ˆ Dimocarpus longana ˆ Sapindaceae Donated by: CRFG/McIntyre and planted in 1980 (r.f.-08) Common names: Dragon‚s eye, Li-chihnu, Mamoncillo Chino 


The longan is a native to southern China, growing there at elevations  from 500’ to 1500’. The longan tree is closely related to the lychee (Litchi chinensis), even though they are botanically placed in a different genus.

The longan  thrives much better on higher ground than the lychee and accepts more frost.

The longan  grows up to 30 feet in height and to 40 feet in width, the rough-barked trunk to 2 feet thick. The tree is erect with slightly drooping branches. The evergreen leaves are lanceolate with  blunt tips, 4 to 8 inches long and about 2 inches wide. The upper surface of the leaf is a glossy green, with undersides a gray-green color with minute hairs. New growth has a burgundy color and is very showy.

The flowers are of a pale-yellow color with 5 to 6 petals, larger than those of the lychee. Flowers are borne in upright terminal panicles, male and female mingled.

The fruits are globose, 1/2 to 1 inch in diameter, grown in clusters,  with thin, yellowish-to-reddish brown skin and rough protuberances but much less prominent than those of the lychee. The flesh is white, translucent, sweet but not as flavored as the lychee.

The seed is round, jet-black, with a circular white spot at the base, giving it the aspect of an eye.

The longan thrives best in rich sandy loam or in soils that are moderately acid, and somewhat organic. In organic muck soils the longan may not bloom or fruit. With long periods of cool weather in the winter months but with no frost, longan trees bloom well. Blooming is poor after a warm winter.

Most longans are grown from seed but seeds lose viability quickly.

Germination takes place within a week. Seeds are planted 3/4  inch deep; otherwise they may send up more than one sprout. Seedlings should be transplanted to a shaded area the following spring and set in the field 2-3 years later during winter dormancy. Grafting is uncommon, and when it is done, longan rootstock is used.  Vegetative propagation is mostly by means of inarching onto 3-5 year old ‘Wu Yuan’ seedlings, characterized by their vigor as a longan rootstock.

The longan is relatively free of pests and diseases. Most of the problems can be related to signs of mineral deficiency, which can be corrected by supplying minor elements during the fertilization program. The longan tree needs an adequate supply of water and can stand brief flooding but not prolonged drought. Pruning is an important operation. Flowers are removed from the clusters, and fruits are removed from the clusters to improve the quality of the fruit.