Autumn, the traditional harvest season in China, breathes life into the Yunzhou district of Datong, Shanxi province. Fields of golden blooms stretch as far as the eye can see, as workers move with purpose through the fields. The process is meticulous — flowers are washed, packed, blanched, dried and boxed with precision.

The once unassuming city of Datong is now becoming the nation's citron daylily hub, producing a quarter of the country's total output. This once overlooked industry now plays a crucial role in the local economy, improving farmers' lives and drawing tourists from across the nation.

From cultivation and harvesting to processing and sightseeing, the citron daylily industry has formed a mature supply chain, generating revenue of 4.2 billion yuan ($592 million) a year. These flowers are not just a local treasure, they are exported to markets in the United States, Canada, Japan and other countries and regions.

Tang Wan, a citron daylily grower in Yunzhou, and his wife enter their field every night around 11 pm to harvest the flowers until dawn. He said high-quality flowers must be picked while still in bud form, before the sunlight causes them to bloom and lose their value.

Typically, the couple harvests over 100 kilograms of flowers and earns around 500 yuan per night.

Tang's hometown, Yunzhou, provides an ideal environment for citron daylily cultivation, which benefits from abundant sunlight, significant temperature variations and nutrient-rich soil.

Yet, the going was not without challenges. Before the citron daylily industry gained momentum, local farmers like Tang struggled with the unpredictability of weather and the long cultivation cycle of yellow flowers, which take four years to mature and do not allow growers to make a profit straightaway.

Tang's early attempts were thwarted by drought, forcing him to abandon his first crop and return to corn farming. "For three years, I planted and dug up, planted and dug up, over and over again," Tang recalled.