The Graden removed organic matter from the greens. This consists of older, decayed roots, turfgrass plants, pollen and other things. It clogs valuable pore space in the greens that new roots would otherwise use and impedes water movement. This is why thatch greens are soft and wet! This is also why it is important to get 20% of it out every year. As fast as we remove it, the turf is accumulating more. The slits created by the Graden machine are filled with new, dry sand.
