As the daughter-in-law of a veteran of the brigade of Chinese Eighth Route Army which led the campaign at that time, Hou and her husband continued to do farm work in the fields cultivated by the brigade after the founding of the People's Republic of China in 1949.
"In the 1950s, the hills were covered by farmland instead of trees. But we barely had much grain yield due to the barren soil and arid climate," Hou said.
With government subsidies, Hou led her villagers to plant trees in the surrounding hills in 1999. Thanks to two decades of reforestation, Nanniwan now has a new look, with all the surrounding mountains covered with green trees in late spring.
"Last year, we successfully planted over 26 hectares of lotus, which attracted plenty of tourists. I had never heard that lotus could grow on the loess plateau. So you know how the environment has changed here," Hou said.
Growing grains failed to help farmers in Yan'an cast off poverty, but planting trees made it.
The vegetation coverage of Yan'an has increased from 46 percent in 2000 to the current 81.3 percent.