Thailand mangosteen export season

Roughly April to August, on almost the same weeks as durian and often in the same booking. That is the useful thing to know about it: mangosteen is at its best and cheapest exactly when vessel space out of Laem Chabang is at its tightest.

The east picks first. Chanthaburi, Rayong and Trat start exporting in April, and their peak is May and June. The south peaks in July and August, and from August southern Thailand becomes the main supply to the Chinese market. A buyer in August is therefore buying different orchards, a different weather history and often a different packer from the one in May.

China takes nine-tenths of it: 91% of the 284,860 tonnes Thailand exported in 2024. The United States is open only to irradiated fruit, under a 2007 APHIS rule. The rule requires a dose of 400 gray applied in Thailand, on fruit from production areas registered with the Thai plant protection authority. Japan dropped its heat-treatment requirement for Thai mangosteen in August 2023, so fruit to Japan now ships untreated after inspection.

The rind does most of the work of keeping the fruit, but it hardens as it dries and a hard rind reads as old fruit to a buyer who has not opened one. Humidity in transit matters as much as temperature on this one.

Cold does the same damage faster. The University of Hawaii postharvest guide gives current practice as 12–14°C, for about 20 days without chilling injury. Below 10°C for more than 15 days, the rind hardens and darkens once the fruit is back at room temperature; at 5°C the injury shows in five days. That is also why a shared box with durian is a compromise: the same guide warns that whole durian suffers chilling injury below 15°C.

Rain shows up as rejects rather than as a later window. Heavy rain while the fruit is growing, even just before harvest, causes translucent flesh. Affected fruit sinks in water, which is how packers sort it out, so a wet season means more fruit left behind at the packhouse.