Repotting guide
When & how to repot Longan (Dimocarpus longan)
Also called Longan, Dragon eye fruit, Lungan.
More about longan
About Longan
Dimocarpus longan · also called Longan, Dragon eye fruit · tropical
Longan, a close relative of lychee, is a subtropical evergreen tree bearing clusters of brown-skinned 'dragon eye' fruit with sweet, juicy flesh. It needs full sun, well-drained acidic soil, and a cool dry winter to flower well. Slightly more cold- and drought-tolerant than lychee but still strictly frost-sensitive.
Mature size: 9-12 m or more in the ground over time; kept to 2-4 m by container culture and pruning.
Watch for — Iron chlorosis: Yellow new growth on alkaline soils. Acidify the root zone and apply chelated iron and trace elements.
How to tell longan needs repotting
Repotting on a calendar is less reliable than reading the plant. For longan, watch for these signs:
- Thick roots out of the drainage holes, or circling the surface and lifting the plant.
- The pot dries out unusually fast and longan wilts between waterings it used to shrug off.
- The plant is visibly top-heavy and tips over easily.
- Stalled growth and small new leaves over a full season — though with a big specimen, top-dressing is often the better first response before a full repot.
For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.
How often to repot longan
Every 2–3 years; top-dress in the in-between years. Longan's growth habit — large, spreading evergreen tree with a broad rounded canopy and glossy compound leaves; moderately vigorous. — sets the pace. Longan, a close relative of lychee, is a subtropical evergreen tree bearing clusters of brown-skinned 'dragon eye' fruit with sweet, juicy flesh. It needs full sun, well-drained acidic soil, and a cool dry winter to flower well. Slightly more cold- and drought-tolerant than lychee but still strictly frost-sensitive.
What size pot to step longan up to
Move up exactly one pot size. A heavy longan dropped into a vastly bigger pot sits in a reservoir of wet soil its roots cannot reach, which rots them and destabilises the plant. In the years between repots, lift off and replace the top 3–5 cm of soil (top-dressing) instead — it refreshes nutrients without the shock of a full repot.
Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.
The best time of year to repot longan
Early spring, just as new growth restarts, is the ideal window for longan. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.
Step-by-step: repotting longan
- Consider top-dressing first. If longan is not badly root-bound, scrape off and replace the top 3–5 cm of soil instead — far less shock for a big plant that hates moving.
- Get help and one size up. For a full repot, choose a pot just one size larger. A heavy plant needs two people and a stable, free-draining pot.
- Ease it out on its side. Lay the plant down, slide the pot off, and gently loosen the outer roots. Do not bare-root a mature specimen.
- Repot at the same depth. Add fresh deep, well-drained, slightly acidic loam beneath and around the rootball, keeping the original soil line. Firm it so the trunk is stable and upright.
- Water and leave it put. Water thoroughly, then leave longan in the same spot and light — moving and repotting at once is what makes it drop leaves.
Aftercare
Leave longan in exactly the same spot and light it was in before — moving and repotting at the same time is what makes a big specimen drop leaves. Water it in well, then let the top of the soil dry before watering again so the larger volume of fresh soil does not stay sodden. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.
The right soil mix for longan
Longan wants deep, well-drained, slightly acidic loam. Adaptable but happiest in fertile, free-draining soil around pH 5.5-6.5. Tolerates a wider range of soils than lychee yet still resents poor drainage and strongly alkaline ground. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.
Repotting longan — frequently asked questions
How often should you repot longan?
Every 2–3 years; top-dress in the in-between years for longan. Fully repot longan only every 2–3 years; in the in-between years just top-dress the top 3–5 cm of soil. Step up one pot size in spring with deep, well-drained, slightly acidic loam. It is heavy and hates being moved, and a vastly oversized pot holds water against the roots and rots them.
What size pot does longan need?
Move up exactly one pot size. A heavy longan dropped into a vastly bigger pot sits in a reservoir of wet soil its roots cannot reach, which rots them and destabilises the plant. In the years between repots, lift off and replace the top 3–5 cm of soil (top-dressing) instead — it refreshes nutrients without the shock of a full repot. Use our pot size calculator to size it from the plant's current pot and root spread.
When is the best time of year to repot longan?
Early spring, just as new growth restarts, is the ideal window for longan. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.
Should you top-dress or fully repot longan?
For a big, heavy longan, top-dressing — replacing the top 3–5 cm of soil — is the gentler option most years, with a full repot only every 2–3 years. A mature specimen sulks and drops leaves when fully repotted, so do it as rarely as the roots allow.
Should you fertilise longan after repotting?
Not immediately. Wait about 4 weeks after repotting longan. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.
Related guides
- Longan care — light, water, soil and common problems
- How often to water longan — the watering brief
- How to repot a plant — the complete step-by-step method
- Root-bound plant — how to spot and fix it
- Pot size calculator — size the next pot correctly
- When & how to repot monstera
- When & how to repot pothos
- When & how to repot fiddle leaf fig
- All 5561 repotting guides in the Growli library