Longan - Diamond River
Dimocarpus longan 'Diamond River'
Common Names: Diamond River Longan, Dragon Eye Fruit
Local Name: Puvatti Pazham (Tamil), Longan (Hindi/English)
Family: Sapindaceae
Origin: China/Vietnam (selected cultivar); species native to Southeast Asia
Plant Type: Perennial evergreen tree
Variety: Diamond River โ compact, self-pollinating variety with consistent bearing and sweet fruit
Average Lifespan: 40โ60+ years
๐ฟ Botanical Description
| Growth Habit | Medium evergreen tree with dense, rounded canopy; more compact than standard longan |
| Plant Size | 5โ8 meters tall; canopy spread 4โ6 meters (smaller than typical longan) |
| Leaves | Alternate, pinnately compound, 4โ8 pairs of leaflets, 6โ15 cm each, dark green, leathery |
| Flowers | Small, yellowish-white, in large terminal panicles (20โ40 cm); functionally male, female, and bisexual |
| Flower Characteristics | Self-pollinating; fragrant; attracts bees and other pollinators |
| Fruit | Round, 2โ3 cm diameter; thin tan-brown shell; translucent white sweet flesh around single seed |
| Fruit Color | Tan to light brown smooth shell; translucent white to pinkish flesh |
| Seed Characteristics | Single round, shiny black seed (resembling a dragon's eye); not edible |
| Root System | Moderately deep with spreading lateral roots |
โ Growing Conditions
| Climate | Tropical to warm subtropical; needs brief cool period to induce flowering |
| Temperature Range | 20โ30ยฐC ideal; needs cool nights (10โ15ยฐC) for flower induction; frost-sensitive |
| Rainfall Requirement | 1200โ2000 mm annually; dry period before flowering beneficial |
| Soil Type | Well-drained sandy loam to loam; rich in organic matter |
| Soil pH Preference | 5.5โ6.5 |
| Sun Requirement | Full sun (6โ8 hours daily) |
| Spacing | 5โ6 meters between trees (compact variety) |
| Irrigation Method | Drip irrigation; reduce watering before flowering |
| Water Requirement | Moderate; consistent moisture during fruit development |
| Can it Grow in Pots? | Yes, excellent in large containers (40โ60 liters); compact habit suits container growing |
๐พ Cultivation & Care
| Fertilizer Schedule | 3โ4 times per year; increase potassium during fruiting |
| Recommended Organic Fertilizers | Compost, vermicompost, fish emulsion, bone meal, seaweed extract |
| Pesticide Frequency | Monitor monthly; treat during flowering and fruiting |
| Recommended Organic Pesticides | Neem oil, insecticidal soap, pyrethrin |
| Mulching Practice | Organic mulch (5โ8 cm) to retain moisture |
| Training System | Open center; maintain compact form |
| Pruning Time | After harvest; tip-prune to maintain shape |
| How to Prune | Remove dead wood; tip-prune new growth after harvest to encourage flowering wood |
| Common Pests | Longan stink bug, fruit borer, mites, lychee erinose mite |
| Common Diseases | Witches' broom, leaf spot, fruit rot, powdery mildew |
| Disease Prevention & Remedies | Good air circulation, copper fungicides, remove infected panicles, proper sanitation |
๐ธ Flowering & Fruiting
| Flowering Months | FebruaryโApril (after cool period) |
| Fruiting Season | JuneโSeptember |
| Days to Harvest | 120โ150 days from flowering |
| Harvest Indicators | Shell turns tan-brown, flesh becomes translucent and sweet, fruit detaches easily |
| Average Yield per Plant | 30โ80 kg per tree per year (mature); consistent bearer |
| Pollination Type | Self-pollination (Diamond River is self-fertile) |
| Pollination Notes | Does not require a second tree; bees improve fruit set |
๐ฑ Pollination & Propagation
| Pollination Details | Self-fertile; produces both male and bisexual flowers on same panicle |
| Propagation by Seeds | Seeds germinate in 1โ2 weeks; not true-to-type; seedlings take 6โ8 years to fruit |
| Propagation by Cuttings | Air layering (marcotting) is common and effective |
| Propagation by Grafting | Cleft or veneer grafting on seedling rootstock; fruits in 2โ3 years |
๐ง Environmental Impact & Sustainability
| Water Usage | Moderate; efficient with drip irrigation |
| Soil Conservation Practices | Evergreen canopy provides year-round cover; mulching prevents erosion |
| Organic Practices Used | Composting, biological pest control, cover cropping |
| Companion Plants | Leguminous cover crops, lemongrass, marigolds |
| Biodiversity Benefits | Flowers attract bees and pollinators; fruit eaten by birds |
๐ฐ Economic Importance
| Commercial Production Regions | China (Guangdong, Fujian), Thailand, Vietnam, Australia, USA (Florida, Hawaii) |
| Market Uses | Fresh fruit, dried longan, canned in syrup |
| Processing Uses | Dried longan (gui yuan), longan honey, beverages, desserts, traditional medicine |
| Market Value (Approx.) | โน200โ500 per kg (fresh); dried longan commands higher prices |
๐ฟ Cultural Significance
| Symbolism | Called "Dragon Eye" (้พ็ผ) in Chinese; symbol of good luck and fertility |
| Traditional Uses | Dried longan used in Traditional Chinese Medicine as blood tonic; fruit in festive desserts |
๐ Nutritional Information
| Calories | 60 kcal per 100g |
| Dietary Fiber | 1.1 g per 100g |
| Vitamin C | 84 mg per 100g (140% DV) |
| Vitamin A | Trace amounts |
| Iron | 0.13 mg per 100g |
| Potassium | 266 mg per 100g |
| Antioxidants | Gallic acid, ellagic acid, corilagin, polyphenols |
| Other Key Nutrients | Riboflavin, niacin, copper, manganese, phosphorus |
๐ฟ Medicinal Uses
| Anxiety & Sleep | Dried longan used in TCM as calming agent and sleep aid; nourishes heart blood |
| Immune Support | Very high vitamin C content supports immune function |
| Anti-inflammatory Properties | Polyphenols and gallic acid show anti-inflammatory activity |
| Heart Health | Potassium and antioxidants support cardiovascular health |
| Digestive Health | Mild fiber content; traditionally used to strengthen spleen and stomach in TCM |
Disclaimer: Information provided is for educational purposes only and not a substitute for medical advice.
๐ธ Photo Gallery
๐ Orchard Observation Notes
Add your field observations here.