Green drainage 101

When considering the health of a green, the most important factor is a superintendent’s ability to manage the moisture in the soil.  Due to this fact, most new greens are built to USGA specifications which include subsurface drainage topped by 16” of sand before the green is seeded or sprigged.  The sand allows water to move quickly through the soil profile and aids in creating a firm surface that is free from the severe disease pressure caused by wet greens.  Over time, a green will accumulate an organic layer of bio degraded roots, shoots, and leaves that acts as a sponge soaking up and retaining water.  Aerification and verticutting are the most common ways of managing and removing this water holding organic matter.  As the organic matter increases, a green will stay wetter, longer.  Once organic matter reaches dangerous levels (4%-6%) the green becomes a good candidate for restoration.  

In the photographs below, notice how the new Bear greens have just a little organic matter (darker in color) while the Bobcat greens are VERY organic.  This is one reason why we have so much disease pressure on the Bobcat greens VS. the new, better draining, less organic Bear greens. 

 

                   BOBCAT GREEN PROFILE                                         BEAR GREEN PROFILE