What's a few degrees matter?

 September is here, and it feels like someone flipped the switch, sending us from oppressive 75 degree mornings, to much cooler temperatures in the upper 50s.  For the turf, this is just what the doctor ordered to aid in recovery.  Looking back at the month of August, in addition to the rollercoaster of "all or none" for rainfall, we ended the month with an average daily high temperature three degrees above normal.

So you might be thinking, yes, it was pretty warm in August, but does three degrees matter?  Well, an argument can be made that when those three degrees are for an entire month, it does have an impact.  In the short term, warmer temperatures over the month may lead us to include an additional application of fungicide for prevention of Pythium Blight on the golf course, which comes at a fair cost.

August is also the month of the year when cool season turfgrass has its shortest roots.  Prolonged warmer temperatures may further delay turf recovery into the meteorological fall.  More warm days also extend the window of opportunity for our insect nemesis, the Annual Bluegrass Weevil, to cause damage.  Of late, for the first time this year, we are seeing weevil damage in Bentgrass.

Bentgrass thinned from weevil damage.

Longer term, warmer temperatures allow weeds, such as Dallisgrass to become further established on the golf course.  Dallisgrass is a warm season (think southern) perennial grass that looks like Crabgrass on steroids.  This weed hadn't been seen on the golf course until a few years ago, and giving it more days to actively grow, isn't what we need.

Again, we are grateful to be in September, and fortunate that the remnants of Hurricane Ida led to nothing more than a soaking rain event for us.  But don't discount the cumulative impact of temperature changes--the weeds, insects, and diseases aren't.