Troubleshooting
Longan problems — and how to fix them
Longan (Nephelium longana) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Failure to flower
Longan requires a cool, dry rest period in autumn/winter (temperatures around 15°C / 59°F for 4–6 weeks) to reliably set flower buds. Trees kept too warm year-round often produce vegetative growth only.
Fruit drop
Premature fruit drop in late spring or early summer is commonly caused by irregular irrigation or a sudden switch from wet to dry conditions during fruit development. Maintain even soil moisture once fruit is pea-sized.
Longan witches' broom (Dimocarpus longan Lychee Erinose Mite)
Eriophyid mites cause abnormal, bunched vegetative growth resembling a witch's broom. Remove and destroy affected shoots promptly; spray with sulfur-based miticide in early spring before new flush.
Prevent longan problems before they start
Most longan issues are care-mismatch, not bad luck. Dial in the basics:
Longan problems — FAQ
Why is my longan failure to flower?
Longan requires a cool, dry rest period in autumn/winter (temperatures around 15°C / 59°F for 4–6 weeks) to reliably set flower buds. Trees kept too warm year-round often produce vegetative growth only.
Why is my longan fruit drop?
Premature fruit drop in late spring or early summer is commonly caused by irregular irrigation or a sudden switch from wet to dry conditions during fruit development. Maintain even soil moisture once fruit is pea-sized.
Why is my longan longan witches' broom (dimocarpus longan lychee erinose mite)?
Eriophyid mites cause abnormal, bunched vegetative growth resembling a witch's broom. Remove and destroy affected shoots promptly; spray with sulfur-based miticide in early spring before new flush.