Repotting guide

When & how to repot Korlan (Nephelium hypoleucum)

Also called Korlan, Korlan Tree.

More about korlan

About Korlan

Nephelium hypoleucum · also called Korlan, Korlan Tree · tropical

Korlan is a rare, semi-wild fruit tree from the Sapindaceae family, native to the rainforests of Thailand, Laos, Cambodia, and Vietnam. Closely related to rambutan, its yellowish fruits have a less spiny pericarp and a translucent, sweet aril that is notably sweeter than rambutan. Rarely commercially cultivated; usually harvested from wild trees in highland tropical forests.

Mature size: 12–25 m tall in the wild; likely maintained at 6–10 m in managed cultivation

Watch for — Root rot in low-drainage soils: Native to well-draining forest soils; compacted or waterlogged soils in cultivation cause rapid root decline. Always plant in raised beds or well-amended free-draining soil.

How to tell korlan needs repotting

Repotting on a calendar is less reliable than reading the plant. For korlan, 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 korlan 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 korlan

Every 2–3 years; top-dress in the in-between years. Korlan's growth habit — medium to large evergreen tree; pinnately compound leaves with pale undersides (hypoleucum = white beneath) — sets the pace. Korlan is a rare, semi-wild fruit tree from the Sapindaceae family, native to the rainforests of Thailand, Laos, Cambodia, and Vietnam. Closely related to rambutan, its yellowish fruits have a less spiny pericarp and a translucent, sweet aril that is notably sweeter than rambutan. Rarely commercially cultivated; usually harvested from wild trees in highland tropical forests.

What size pot to step korlan up to

Move up exactly one pot size. A heavy korlan 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 korlan

Early spring, just as new growth restarts, is the ideal window for korlan. 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 korlan

Consider top-dressing first. If korlan 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 fertile, well-draining sandy loam to 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 korlan in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave korlan 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 korlan

Korlan wants fertile, well-draining sandy loam to loam. Naturally found in fertile forest soils rich in organic matter. Performs best in sandy loam with excellent drainage; tolerates slightly higher altitude conditions up to 1,200 m where soils tend to be loamy and humus-rich. pH should be slightly acidic, 5.5–6.5. Avoid heavy, poorly drained soils. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting korlan — frequently asked questions

How often should you repot korlan?

Every 2–3 years; top-dress in the in-between years for korlan. Fully repot korlan 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 fertile, well-draining sandy loam to 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 korlan need?

When is the best time of year to repot korlan?

Should you top-dress or fully repot korlan?

For a big, heavy korlan, 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 korlan after repotting?

Not immediately. Wait about 4 weeks after repotting korlan. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.