Native to south east Asia and since distributed to other countries in the tropics. It is thought to have arisen as a polyploid hybrid between 2 other Garcinia species.
Adapted to humid tropical lowlands up to 1000m with temperatures of 27-36°C. Below temperatures of 20°C growth slows and 3-5°C will kill trees.
The evergreen dioecious trees are 5-20m tall and have a pyramidal crown. The opposite coriaceous glabrous olive-green leaves are oblong-elliptical, 15-25 X 7-13cm, The root system is poorly developed and also has very few root hairs.
Clusiaceae (Guttiferae) Family. There are more than 200 species in the genus and two thirds of them produce edible fruit, some being button mangosteen or cherapu, gamboge, bacuri, imbe, madrono and achachairu. Taxonomy of the family has been controversial. There are also several native Australian species.
A wide range of well-drained soils is tolerated, but sands or limestone soils low in humus are detrimental.
The seeds are extremely recalcitrant and best kept moist or left in the flesh till sowing. They can germinate in 2-3 weeks but growth is slow. Care must be exercised when transplanting because of the long, delicate taproot. Wedge grafting can be used but cuttings and marcots have been unsuccessful. Self-grafted plants have a shorter juvenile period but are slower growing and produce smaller fruit. Although apomixis means propagation will be clonal from an individual tree, there can be substantial genetic variation between different trees. Some mangosteen seeds are polyembryonic.
The solitary or paired terminal flowers have 4 sepals and petals, a globose ovary with a 4-8 lobed stigma and staminodes. They are borne on the tip of older branches throughout the canopy. Staminate trees are thought not to exist. Once bud initiation has been induced by a dry period and watering thereafter is regular and sufficient, fruit set can be 30-35%. For a long while, it was thought that all mangosteen trees were genetically identical. It is now known this is not true, there are small genetic differences. However, pollination is not required to set fruit.
Young plants should be shaded for the first 2-4 years and can then be exposed to full sun. For this first period they should be watered during any dry periods. They have a tendency for alternate bearing which can be minimised with management Mature trees may require 2-7kg of complete fertilizer pa; it is usually given in split amounts after harvest and anthesis. Mulch is beneficial.
Mangosteen should be protected from strong winds. The roots of mangosteens are often poorly developed. Trimming the taproot when repotting small trees may encourage more lateral root branching.
Does not require extensive pruning apart from size containment, removal of dead wood, suckers and water sprouts when not flowering or carrying fruit.
The smooth globose berry, 4-6cm diameter, devlops parthenocarpically and has a persistent basal calyx. The pericarp, 6-10mm thick, turns purple on ripening. The white edible aril is 4-8 lobed and contains the apomictic seeds. When mature, the seeds are easily separable from the flesh. Copious latex is present in immature fruit but this disappears with maturity. Edible flesh is only 25-30% of the whole fruit. It’s best nutritional attribute is maybe a good fibre level; carbohydrate content is about 15%.
Juvenility can extend to 20 years, but if well-managed this can be reduced to 5-7. Fruit development may take up to 6 months in cooler areas. Mature trees can produce 200-1500 fruit/tree pa, and up to 3000 have been reported in older specimens (45yrs old). Fruits are picked, with peduncle attached, every 2-3 days when soft and purple; fallen fruit are significantly damaged. The harvest period may last 6-12 weeks. They can be stored at 12-14°C for about 20 days without chill injury.
They are often regarded as one of the best tropical fruits ('Queen of Fruits') and are largely eaten fresh for their aroma, texture and delicious flavour rather than any nutritional qualities. They can also be frozen. Many other forms of processing have been unsuccessful as flavour is lost and pulp darkens. Eat mangosteen fruit when their skin still has a little 'give' to it. Use your thumb and fingers to crunch the shell around the equator of the fruit until you can break the two halves apart, or make an equatorial cut in the skin and then twist one half off. Very hard skin means the fruit is probably past its best.
Mangosteen is resistant to most pests and diseases. The thick astringent skin discourages damage by insects and animals. Nevertheless, ants, rodents, grasshoppers, mites and weeds can pose problems. Infections by some fruit fly species limit world trade.
Mangosteen is ultra-tropical and not for Perth unless you have a large greenhouse. For fruit that is similar to mangosteen and slightly more feasible, see the entries under gamboge and achachairu.