This week, we began topdressing the greens. This means that we put a light coat of sand on the top of the playing surface and then drag it into the turf canopy. This achieves two things: 1) it smooths out any bumps or dips that might be on the green and 2) it dilutes any thatch that might be on the green.
Smoothing the green out makes the greens "faster" and a ball will roll further when putted. It will also make the ball roll more "true", meaning that the ball will roll where you intend it to go.
Thatch is a build-up of organic matter between the soil and the grass leaves. Thatch is mostly comprised of decaying stolons and rhizomes and not leaf blades. Despite popular misconception, removing the grass after cutting has no effect on thatch build-up. A little thatch is a good thing for the grass, as it will protect the crown of the plant from traffic, ie, being stepped on. Too much thatch, however, will harbor insect and fungal pests as well as prevent water from reaching the soil.
Before topdressing, we also ran a verticutting unit over the greens before putting down the sand. This is a rotating blade that digs down into the thatch and brings up some of that organic matter, as well as cuts any grass blade that might be laying over. Because of this, we can incorperate some of the sand into the thatch layer and we can also eliminate any grain that develops on the playing surface.
After putting down the sand, we drag a brush over the green to work the sand into the turf. After we are done, the green will be slightly "slower" than normal, but once the grass starts to grow back through the sand, it will be back to normal and hopefully, even faster.