How to Grow Duku

Duku

Lansium parasiticum

tree

Duku is a tropical fruit tree native to Southeast Asia, producing clusters of small, round, yellowish fruits with thin, smooth skin and sweet, translucent flesh. The tree grows to moderate height and is valued for its delicious fruit, which is often called 'langsat' in some regions. It thrives in warm, humid tropical climates and requires consistent care for optimal production.

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Example Duku timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Duku

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Duku

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Duku dates for your own zip code.

Growing Conditions

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Sun: Full sun, 6-8 hours daily; tolerates partial shade
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Water: Regular watering to keep soil consistently moist but not waterlogged; reduce frequency during dry season; requires high humidity (60-80%)
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Spacing: 360 inches
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Days to maturity: 2000-2400 days (5-7 years from grafted sapling to first fruit)
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Planting depth: Transplant at same depth as nursery container; seeds planted 1 inch deep

Soil

Type: Well-draining loamy soil with organic matter
pH: 5.5-6.5
Amendments:
Compost Aged manure Peat moss Sand for drainage

Growing Zones

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Thrives in tropical zones 10b-11, requiring consistently warm temperatures year-round

10b 11a 11b

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Growth Stages

1

Seedling

4-6 weeks

Young plant with 2-4 true leaves, small and tender with pale green coloration

Keep in bright, filtered light; maintain high humidity; water gently to avoid damping off; provide protection from wind

2

Juvenile/Establishment

1-2 years

Young tree developing main trunk and primary branches, 2-4 feet tall with increasing leaf size and stem thickness

Stake for support in windy areas; mulch heavily; establish regular watering schedule; begin light fertilization monthly; prune to shape form

3

Vegetative Growth

2-4 years

Tree rapidly expanding canopy, 6-15 feet tall, producing numerous branches and dense foliage

Continue mulching; water deeply and regularly; apply balanced fertilizer every 2-3 months; thin branches for air circulation; prune lower branches for easier harvesting

4

Flowering & Fruiting

3-4 months flowering; 2-3 months fruit development

Tree produces small cream to pale yellow flowers in panicles, followed by 1-2 inch round fruits in clusters; fruits develop yellow to brownish skin

Reduce nitrogen fertilizer to encourage fruiting; maintain consistent moisture during fruit development; thin excess fruit for larger individual fruits; protect from strong winds during heavy fruit load

5

Mature/Production

Ongoing (10+ years of production)

Established tree 20-30 feet tall producing heavy annual or biennial fruit crops; fruits ripen to golden-yellow with characteristic aroma

Maintain deep watering schedule; apply potassium-rich fertilizer monthly during growing season; annual light pruning to maintain shape and air flow; harvest ripe fruit promptly; monitor for pests and diseases

Companion Planting

Plan your garden →

Plant with:

Calamansi Coconut palm Mango Cacao Legumes (nitrogen-fixing understory)

Avoid planting near:

Walnut trees (allelopathic) Black pepper (competing root systems) Dense shade-producing trees

Common Pests

  • Remove fallen fruit; use fruit bagging; apply organic insecticide if severe; maintain sanitation

  • Spray with horticultural oil; prune heavily infested branches; encourage natural predators

  • Spray with neem oil; use insecticidal soap; remove with water spray; maintain low nitrogen

  • Hand-pick if population is low; use Bacillus thuringiensis (Bt); maintain tree vigor

  • Prune affected branches; maintain tree health; wrap trunks to prevent egg-laying

Uses

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Fresh fruit consumption and juice

Culinary

Duku fruits are eaten fresh as dessert fruit, with sweet translucent flesh similar to grapes; the fruit is also processed into juices, smoothies, and preserves. The flavor is often compared to a cross between grapes and muscat, with subtle floral notes. [source]

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Traditional medicine and antimicrobial properties

Medicinal

In Southeast Asian traditional medicine, duku leaves, bark, and seeds are used to treat fever, dysentery, and skin conditions. Research indicates the plant contains compounds with antimicrobial and antioxidant properties. [source]

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Pest repellent and wood products

Household

Duku seeds and bark are traditionally used as natural insect repellents; the wood is valuable for tool handles and small furniture due to its hardness and durability. [source]

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Wildlife food source

Wildlife

The abundant fruit production makes duku valuable for supporting tropical fruit-eating wildlife including birds, bats, and primates in agroforestry systems. [source]

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Pickled and fermented preparations

Culinary

In traditional Southeast Asian cuisine, unripe duku fruits are pickled and fermented with spices and salt as condiments, providing a sour, umami-rich flavor component to rice dishes and curries. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Duku fruits mature 3-4 months after flowering; harvest when fruits turn golden-yellow and emit sweet aroma, typically July-September in Southeast Asia; pick entire clusters or individual ripe fruits by hand; fruits continue ripening slightly after harvest; handle gently to avoid bruising thin skin; ripe fruits store 5-10 days at room temperature or 2-3 weeks refrigerated

Fun Facts

  • 🌱 Duku is sometimes called 'langsat' or 'longkong' in different Southeast Asian regions, though true langsat (Lansium domesticum var. pubescens) is a separate but closely related species with hairy fruits
  • 🌱 The tree can produce 200-600 fruits per harvest season, with fruits typically borne in distinctive grape-like clusters containing 5-30 individual fruits
  • 🌱 Duku has a biennial or alternate-bearing pattern in some cultivars, producing heavy crops one year and lighter crops the next, which can be managed through pruning and fertilization

Gardening Terms

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