Can Yunnan dig down mountain piles in September?

Of course. Downhill pile is a kind of wild bonsai material, which is usually excavated and transplanted in the late dormant period to improve the survival rate. Different tree species have different planting time, but most of them are suitable for planting in autumn, winter or spring. September in Yunnan belongs to the early autumn season, and the climate is mild, so you can dig piles down the mountain.