How to Grow Longan
Dimocarpus longan
Grow longan in a heated greenhouse or large conservatory in the UK, maintaining a minimum of 10°C in winter. Give it the brightest position available with full sun and water freely during the growing season. Longan is more heat-tolerant than its relative lychee but still cannot survive UK winters outdoors. Prune regularly to control size in a container and feed fortnightly from spring to autumn.
Yearly Lifecycle
Care Essentials
Feed fortnightly with a balanced liquid fertiliser from spring to autumn. Reduce to monthly in winter. Longan is a moderately hungry tree that benefits from consistent feeding during active growth.
Watch For
- Scale insects
- Mealybug
- Red spider mite
- Root rot from overwatering
- Sooty mould
Track your Longan care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Full sun, brightest position in heated greenhouse
Full sun in the brightest position available. Longan needs strong light and warmth to thrive. A south-facing heated greenhouse or conservatory is ideal.
💧 Watering
Freely in summer, reduced but not dry in winter
Water freely during the growing season, keeping compost evenly moist. Reduce in winter but do not allow the rootball to dry out completely.
🌱 Fertilizing
Balanced liquid feed fortnightly, spring to autumn
Feed fortnightly with a balanced liquid fertiliser from spring to autumn. Longan is a moderately hungry tree that benefits from regular feeding during active growth.
✂️ Pruning
Spring pruning to control size and shape
Prune to control size and shape in spring. Remove dead wood and crossing branches. Longan can grow large, so regular pruning helps manage it in a container.
❄️ Overwintering
Heated greenhouse above 10°C, reduce care in winter
Keep in a heated greenhouse above 10°C. Longan is more heat-tolerant than lychee but still cannot survive UK winters outdoors. Reduce watering and feeding in winter.
Growing Tips
Maximum light and warmth
Provide the brightest position available in a heated greenhouse or conservatory. Longan needs strong light and warmth to thrive and has any chance of fruiting.
Even moisture in summer
Water freely during the growing season, keeping compost evenly moist. Reduce in winter but never let the rootball dry out completely.
Prune to control size
Prune in spring to control size and shape. Longan can grow large, so regular pruning is essential to manage it in a container.
Monitor greenhouse pests
Watch for scale insects, mealybug, and red spider mite under glass. Introduce biological controls early before populations build up.
Pests & Diseases
Pest Scale Insects
Identification: Small brown or white bumps on stems and leaf undersides, sticky honeydew and sooty mould
- Wipe off with a cloth dipped in soapy water
- Introduce parasitic wasps as biological control under glass
- Spray with plant oil-based insecticide
Pest Mealybug
Identification: White cottony masses in leaf axils and on stems, sticky honeydew
- Dab with a cotton bud soaked in methylated spirit
- Introduce Cryptolaemus ladybird as biological control
- Spray with fatty acid or plant oil-based insecticide
Pest Red Spider Mite
Identification: Fine webbing on leaf undersides, stippled yellowing leaves, tiny mites visible with a hand lens
- Increase humidity by misting regularly
- Introduce predatory mite Phytoseiulus persimilis
- Spray with fatty acid-based miticide
Disease Root Rot Phytophthora spp.
Symptoms: Yellowing leaves, wilting despite moist soil, dark mushy roots, plant collapse
Treatment: Remove from pot, trim rotten roots, repot in fresh free-draining compost. Reduce watering
Prevention: Use well-drained compost. Ensure pots have adequate drainage holes
Disease Sooty Mould
Symptoms: Black powdery coating on leaves and stems, growing on honeydew from sap-sucking insects
Treatment: Wipe off with a damp cloth. Control the underlying pest problem
Prevention: Monitor for and control sap-sucking pests promptly
Spacing & Planting
| Plant spacing | 900 cm |
| Row spacing | 1100 cm |
| Mature height | 600 cm |
| Mature spread | 500 cm |
Large evergreen tree related to lychee. More heat-tolerant than lychee. Off-season flowering possible.
Log Longan in your garden — track growth, care, and harvests year after year
Start planning free