Today the 4" gravel layer is being installed in the PG. The layer is also known as a choker layer in a USGA spec green. The point of the choker layer is to bridge the gaps between sand and gravel. Otherwise, during rain events, the sand would run out the drain pipes. This obviously would not be good. Once again, the 4" consistent depth of gravel matches the subgrade which also matches what the final grade on the surface will look like. As you see these photos, I hope you begin to understand the science and art behind turfgrass management and construction. You can also see why putting green construction is not an inexpensive proposition!
