Tea fans for air movement on bentgrass greens
I had thought the fans in the tea fields of Shizuoka were used to reduce fungal diseases of the foliage during hot and humid weather. I’ve learned that the actual reason for these fans is to prevent frost from forming on the leaves during winter, by blowing warmer air (cold air is heavier, and sinks) down to the plants.
These same fans are used on many golf courses in Japan to improve air movement across creeping bentgrass greens during summer.
The fans are usually painted brown and are kept relatively distant from the green surface, blending right in with the pine trees around the green. These tea fans (o-cha senpuki) are also quiet, and I’ve been assured by Japanese greenkeepers that they do cause a noticeable improvement in bentgrass greens, without causing too much disturbance to golfers.