2010 was a brutal year for turf and landscape maintenance. Heavy spring rains saturated, drowned and killed our root systems then summer unleashed 90 degrees plus temperatures for weeks. We did more fall renovation work last year than we'd done in nearly the previous three years combined.
So there is no way 2011 could be hotter, right? Guess again, during 2011 our soil temperatures have been 10-15% higher than last year. Especially over the last three weeks, cool season grasses have really struggled, especially because there was no cooling off periods at nighttime. As a matter of fact, the last 15-19 consecutive nights until last week were warmer than the 25 year average high temperatures during the day. High temperatures cause problems both above and below ground. Above ground, photosynthesis or energy production of cool-season turfgrasses starts to decline once daytime air temperatures exceed 70-75F. At the same time, respiration (the energy-consuming process to maintain the plant) is increasing with higher temperatures. Below ground, root growth of cool-season turfgrass is optimal between 50 and 65F and declines quickly above 70F. At the same time, root death increases at elevated temperatures, especially in wet soils with limited ability to hold oxygen. The end result is that root systems become shallow with prolonged heat and thus have limited ability to take up water and nutrients. This causes even the healthiest of turf to thin, weaken and potentially die. Please let us know if you have any questions. Here’s to hoping the HEAT WAVE of 2011 is behind us!