This photograph shows newly emerged bentgrass seedlings growing in a sand medium, much like our greens at HCC. Sand not necessarily the best growing medium for turf. It doesn't retain water nor does it hold onto nutrients. Therefore, it requires a lot of inputs to create a healthy playing surface. At HCC, we spray greens every Thursday with a fertilizer solution. For this reason, greens are usually built from a 80% sand-20% peat moss mix or a 90%-10% mix. The peat moss allows for some nutrient and water retention. However, the primary benefit of sand is good drainage. Particularly in Highlands, we can get a 2" rain and you can be back out there golfing in no time. In fact, because of your awesome support and patience, our greens still drain at 14 inches per hour (a phenomenal number given the greens are 15 years old) because of the maintenance practices we employee. Overtime, organic matter and thatch will slow this down, sometimes to the point of failure. At this point, greens rebuilding is the only solution! This is why regular topdressing and aerification are required.
Growing turf in sand is essentially like growing grass in glass beads. On the flip side, you have probably heard the term 'push up' green. This is when the builder of the course pushed up all of the quality top soil in a given area, mounded it and created the green (Typical od very old Clubs). It had excellent nutrient and water holding capacity but lacked good drainage. You might remember HCC greens pre-1999. If we received a lot of rain they were very soft, muddy and even closed if too wet. Soil compaction is an issue.
In our climate of a temperate rain forest, sand is the only way to go. Push up greens are rarely built anymore; particularly because of golfer demands for perfection. In a sand based root system, we as superintendents essentially have total control of inputs, drainage etc that we wouldn't otherwise have with "push ups."