This can be partly attributed to the increase in the topdressing of the greens with spin-type applicators. Other times sand accumulates at the collar’s edge as a result of brushing sand into the turfgrass canopy or aeration holes, following a topdressing application. More specifically, the circular patterns commonly used to brush or drag the sand into the turf push sand that doesn’t work its way into the canopy to the outer edges of the greens, where it accumulates in the collars. This often goes unnoticed at the time because the higher height of cut in the collars allows the turf to receive more sand.
Eventually this creates buildups, or “artificial collar dams, “ blocking surface drainage off the putting surface.