Soil Temperatures Since 2005

Over the winter, I had the opportunity to gather and analyze some climate data from the past decade.  One chart in particular I thought interesting enough to share with the golf and turf community.  The following chart summarizes average soil temperature at a 4-inch depth from 2005-2010.  It confirms what superintendents and golfers already know: 2009 was an unusually favorable year for cool-season turf, and 2010 unusually unfavorable.  

Click on image for a larger view

The peaks of the trendlines are about 5 degrees apart.  That is a huge difference, especially considering that our major turf species prefer soil temperatures well under 70 degrees.  A trend of average soil temperature over 75 degrees is a difficult summer, especially for Poa annua.

I fully admit that I produced this chart to put my mind at ease!  2010 was my second year as a superintendent and I needed some scientific confirmation:  Yes, there was something very different about 2010 -- and it doesn't happen every year.  The take-away message of 2010 for me:  Superintendents have to work to make improvements during those "easier" years to get as much turf as possible through those tough years.