Dimocarpus longan

Longan (Dimocarpus longan)
Scientific name	Dimocarpus longan
Common names	Longan, dragon's eye
Genus	Dimocarpus
Family	Sapindaceae
Order	Sapindales
Growth form	Evergreen tree with a many-branched crown
Native range	Southern China through the eastern Himalaya and mainland Southeast Asia, extending into the Malay region
Native biome	Humid mountain woodland, including forest understorey and secondary formations
Mature height	Usually 9 to 14 m; reports of 25 m or more
Climate and hardiness	Warm subtropical to tropical; a distinct cool season with little or no frost supports flowering
Soil	Fertile, moist, well-drained soil; regional pH reports center around 5.5 to 6
Sun and humidity	Sun to partial shade; protect from the strongest heat while maintaining airflow
Propagation	Fresh seed, air-layering, grafting, and other vegetative methods
Years to fruit	Seedlings 7 to 10 years; vegetatively propagated trees about 2 to 5 years, reported ranges
Fruit	Tan to brown fruit in clusters, with translucent aril around a dark seed
Harvest	Seasonal crop after flowering; harvest timing follows local cool/dry and wet-season cycles

Longan (Dimocarpus longan) is an evergreen fruit tree in the genus Dimocarpus, family Sapindaceae, and order Sapindales. Its tan fruits are borne in clusters and contain a translucent whitish aril around a dark seed. The species is closely associated with monsoonal climates in which a short cool or dry interval can precede flowering.^[1][2]

Description

Longan leaves.

Longan is usually a 9 to 14 m tree with a many-branched crown, although regional sources report trees reaching 25 m or more. It is evergreen and is commonly cultivated as a small tree when regularly pruned. The fruit is a round drupe with a tan to brown peel, translucent sweet aril, and a dark seed. Fruit is produced in branched clusters rather than singly.[2]

Growing

Kew records Dimocarpus longan across southern and southeastern China, the eastern Himalaya, the Indian subcontinent and mainland Southeast Asia, with additional native records in the Malay region and parts of the Philippines and Indonesia. Useful Tropical Plants describes humid mountain woodland, with the tree occurring in forest understorey and secondary formations. Cultivated trees therefore need warmth and moisture during active growth, but reliable flowering is more closely tied to a seasonal cool or dry signal than to constant lowland heat.[1][2]

Soil

Longan prefers fertile soil with regular moisture and good drainage. Useful Tropical Plants reports a preferred pH around 5.5 to 6 and a wider regional tolerance from about pH 5 to 8. Keep the root zone moist from fruit set through maturity, but do not confuse moisture demand with tolerance of stagnant water. Heavy soil should be raised or improved where rainfall leaves the root crown saturated.[2]

Sun and humidity

Use sun to light shade, with protection from the strongest afternoon heat in hot climates. The tree comes from humid woodland, but a dense canopy still benefits from airflow. In a subtropical site, shelter from drying wind and late freezes is more important than providing a sealed, stagnant high-humidity enclosure.[2]

Seasonal changes

Longan generally needs a distinct cool season of up to about three months with little or no frost to initiate bloom. A short dry period can reinforce the flowering signal; warm winters, constant irrigation, or vigorous nitrogen-driven growth may result in poor flowering. Once fruit has set, maintain moisture through enlargement and maturity. The exact flowering and harvest calendar depends on cultivar, latitude, rainfall, and the timing of the cool and dry periods.[2]

Propagation

Fresh seed is useful for rootstocks and variable seedlings. Useful Tropical Plants reports germination in about 7 to 10 days when seed is sown promptly, but fresh seed should be used rather than treated as storable dry seed. Seedling trees are reported to take about 7 to 10 years to bear. Air-layered and other vegetatively propagated trees are reported to bear in about 2 to 5 years, depending on the maturity of the propagating material, cultivar, rootstock, and climate.[2]

Use air-layering or grafting to preserve a selected fruit type and to shorten the juvenile period. The reported time to fruit is a regional range, not a guarantee for every nursery tree or container-grown plant.

Flowering, fruiting, and harvest

Longan flowers.

Longan flowers are produced in terminal panicles after the seasonal growth cycle. The species is described as usually self-fertile in the cited fruit inventory, but flowering intensity and crop regularity depend strongly on the preceding cool or dry period. A warm winter can produce vegetative growth without a useful bloom.[2]

Harvest follows flowering and fruit development, with the calendar shifting among monsoonal regions and cultivars. Pick clusters when the peel has reached the cultivar's mature tan or brown color and the aril has developed its characteristic translucent, sweet texture. Do not use a single regional harvest month as a universal calendar for longan grown outside that climate.[2]

Fruit and uses

Longan is eaten fresh and is also dried, preserved in syrup, or cooked in sweet and savory preparations. The aril is removed from the peel and seed before serving. Dried longan is an important traditional product in parts of its Asian range, while fresh fruit quality depends on cultivar, harvest maturity, and postharvest handling.[2]

Photos

References

• ↑ [1] Plants of the World Online, Dimocarpus longan Accepted name and native range; accessed 2026-08-25.

• ↑ [2] Useful Tropical Plants, Dimocarpus longan habitat, soil, seasonal flowering requirements, propagation, fruiting, and uses; accessed 2026-08-25.

Image credits

• Dimocarpus longan fruits.jpg — USDA photo by Scott Bauer, public domain; longan fruit.
• Dimocarpus longan leaves.jpg — Gihan Jayaweera, CC BY-SA 3.0; longan leaves.
• Flowers for longan.jpg — PQ77wd, CC BY-SA 4.0; longan flowers.
• Starr-090721-3284-Dimocarpus longan-habit-Wailuku-Maui (24675013490).jpg — Forest and Kim Starr, CC BY 3.0 US; tree habit at Wailuku, Maui.