There’s a new gold rush in Southeast Asia, but the prize is not quite so shiny – think green and spiky.

A retired police chief is chasing it. Someone else just built a flashy new house with the income earned from it. Cashew and coffee plantations are being flattened to make space. Sorting and processing sheds dot the roadsides.

To get a closer look, take a road trip with Huynh Kuan Thu, a 55-year-old government worker in Ho Chi Minh City. Every two to three weeks he gets into his BMW SUV, battles traffic jams to get out of the southern financial centre and then bounces along a narrow road, packed with steep potholes and sudden oncoming trucks.

He rests overnight in the mountain hamlet of Bao Loc after a five-hour drive, and sets off for another hour on the road at 6.30am the next day.

Finally, a barely marked dirt road well off the highway leads to Thu’s 12-hectare (29.7-acre) plot, where he raises 1,200 durian trees, mostly of the Monthong variety championed by growers in Thailand. He saw the land use rights for sale eight years ago and pounced.