(Megan Kennelly, KSU Plant Pathology)
We all know it has been super hot lately. Yuck! We humans are suffering because of the hot air, but our cool-season turfgrasses are suffering from the high soil temperatures.
I have not had an onslaught of samples yet, but I fear that if this weather keeps up, they will be coming soon. Usually the flood of turf comes in August, but this is shaping up to be a tough year. (If we are lucky, I’ll be wrong and the weather will chill out, the turf will chill out, and WE can chill out!)
I took a look at soil temperatures at the Kansas Mesonet website (click HERE to access it), and I saw that our 2-inch daily max soil temps in Manhattan have been soaring into the 90’s and our 4 inch daily max soil temps have been solidly in the mid to upper 80’s.
Pop quiz – do you remember the optimal 4-inch soil temperature range for root growth in cool-season turf?
…
Got your guess?
…
The answer – 50-65 degrees Fahrenheit. We will not be seeing that again for several months.
When we get into our current range of steamy 80’s and 90’s in the soil, root growth shuts down. Shoot growth is shutting down too. That means, if you lose cool-season turf now it will be very hard to get it back again.
Now, I’ll point you to some prior posts and references that outline some tips on summer stress management.
We sent these two last week, but I’ll post again here.
By Jack Fry: - general tips for water management: https://blogs.k-state.edu/turf/good-water-management-will-help-get-greens-through-midsummer-stress/ By Dale Bremer - using moisture sensors: https://blogs.k-state.edu/turf/water-management-on-greens-with-soil-moisture-sensors/
Here is another old post from last year:
Summer weather can be ruthless when the turf is stressed and rootless
And, finally, in this page, starting on page 6, there is an excellent, clearly-written set of tips on reducing summer stress in putting greens. Really – if you manage putting greens, take a couple of minutes, click here, scroll to page 6, and read these tips.
http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf
