December is a good time to harvest thurian thet

Locals who have never been further away than 4 km from their village ask us with hesitation whether Dokmai Garden’s large, spiny, green fruits are ‘thurian’ (durian) or not? They are ‘thurian thet’ in the Central Thai language, or ‘soursop’ or ‘guanabana’ in English (Annona muricata, Annonaceae).

Yesterday evening I had my first fruit in a long while. It was huge and in perfect eating condition; so soft you could peel it by hand and eat the white pulp with a tablespoon. In fact, taste and texture reminds me of a fruit yoghourt.

Although this Central and South American plant is easy to grow in the Chiang Mai valley, I rarely see it here and I have never seen its fruit in any Thai fruit market. It seems much more common elsewhere in Southeast Asia, such as Vietnam. The Seehamongkol family do not like soursop due to its acidity, so I can enjoy all fruits produced here at Dokmai Garden.

Ketsanee likes ‘noina’, i.e. sweetsop or custard apple (Annona squamosa) which grows in many Chiang Mai gardens, and which is often for sale in the local markets. My experience of that fruit here at Dokmai Garden is that without bagging (or pesticides if you are still into chemical gardening) the fruits mummify due to thirsty insects. All you get without precaution are small, black and dry fruits which remind me of shrunken heads. Soursop seems to stand the insects much better.

I bought one soursop sapling a few years ago which was in a terrible condition, so I had to cut it down to stimulate the growth of new shoots. Since then I have transplanted five more from cuttings from this original specimen, and yesterday’s fruit was from one of those cuttings. The cuttings smell soursop – a most appealing experience! A 30 cm woody cutting is simply stripped from its leaves and inserted into moist sand and kept under shade until the new leaves sprout. A couple of weeks after that you transplant to a sunny or partly sunny place. At Dokmai garden we water these fruit trees all year round, and they grow much easier than durian (Durio zibethinus, Malvaceae) which is not related (different family, different flavour, different continent).

The international name Annona muricata was coined by Linnaeus in 1753. ‘Annona’ is the Latinized form of the vernacular name for the related cherimoya fruit (Annona cherimola) in the American indian language Taino. ‘Muricata’ means ‘shaped like murex’, Aristotle’s name for a marine mollusk with spines used for the production of purple dye. When Linnaeus wrote “pomis muricatus” in the species description he meant that the fruits have spines, but they are soft. I have only seen real cherimoya once in Thailand, at Ketsanee’s land in Mae Khanin Tai in the nearby Opkhan national park. I have not had the time to transplant it to Dokmai Garden yet.

VIP card holders can pick up seeds or cuttings of soursop for free as long as they are available. If you have an organic fruits and vegetables account with us, come and harvest!

Does anyone in Thailand or Laos have seeds of Rollinia deliciosa? It is high on our wanted list.

Text & Photo: Eric Danell

Morning dew at 08 a.m.