Greens Update and Outlook

Now that we have completed aeration, we are hoping for some good weather to help speed recovery.  We had frost on the second day of aeration and temperatures have remained cooler than ideal.  While it was nice to get some rain following the task, we didn't need 3.25" in 4 separate events over 7 days.  We need some sunlight and warmer temperatures to get things going. 

Despite our efforts to improve air and water flow through the greens profile, we still struggle with extremely slow infiltration rates.  In the picture below you can see standing water from the 1.4" rain that fell 3 days following aeration.  This rain fell over the course of several hours and should not have resulted in puddles.  Just 3 days prior to this rain we put thousands of 1/2" diameter holes in each green.  About 1/3 of those holes were 9" deep and the others were 3" deep.  Good clean coarse sand was used to fill the holes.  The drain outlets are clear and water moves freely through the drain lines, but it takes too long to get to those lines.

Cross section of a USGA green. 
12" sand based root zone over 4" gravel layer over 4" drain pipes

Greens are built on 12" of sand over 4" of pea gravel over a maze of drainage pipes.  To summarize...as greens age, the 12" rootzone becomes "clogged" and the rate of water infiltration slows.  Air porosity in the profile decreases while water porosity increases.  This can be amended with cultivation such as aeration.  However, the benefits of a single aeration don't last long and the process must be repeated.  If the aeration schedule isn't aggressive enough to "catch up", the greens will continue to decline.  We need to give serious thought to doing more than we currently do in order to "flatten the curve" as we hear daily now.  

Visible old aeration holes are underlined.  You can see that they no longer reach the surface. 
They have become "clogged" with organic matter.

This is a new aeration hole filled with sand.  In a few months it
will become "clogged" and resemble the old holes in the picture above.

Greens that hold too much moisture have disease issues, shallow rooting, poor durability in extreme conditions, and are obviously very soft when wet.  Weakened bentgrass from poor soil is replaced with poa annua (annual bluegrass).  Then we have more disease and insect pressure specific to that variety of turf.  It's a vicious cycle. We've suffered for the past several years as the greens profile has deteriorated at an increasing rate.  Looking back through this blog you'll find summer articles that reference this issue.  With all the recent rains and a long range forecast of record heat, we expect to have some challenging times ahead this summer.  

For the next 3-4 months we will be using small solid tines frequently to "vent" the top few inches of soil.  This is a "band aid" to help get us to the next aeration in late August.  We will be lightly topdressing greens regularly to "dilute" the organic matter at the surface.  Wetting agents that help to promote water movement through the profile will also be used.  Hand watering with hoses will be the primary source of supplement to rain in order to ensure that water goes exactly where it is needed.  These are things we do every summer, but we will increase the frequency this year.  Thankfully these practices do little, if anything, to disrupt play.  

Thanks as always for your patience with our efforts.