Summer Stress

Photo, courtesy of Josh Ward, of standing water after one of the summertime storms 

 The words of a very wise and famous man pretty much summed up the course conditions over the last month, "Boy that escalated quickly. I mean, that really got out of hand fast!" Yes, as the Ron Burgundy quote alludes to, the condition of the cool season turf on the golf course has really deteriorated fast. In the middle of June, high off the great spring season we had and adhering to the constant suggestion from my wife to be more optimistic, I wrote a blog post about the great early summer conditions. Sensing my optimism, Mother Nature then proceeded to pound us with the worst summer time weather for turf in recent memory. What happened? Here is a post mortem of the summer turf decline.

• During the month of July, the WHCC golf course experienced over 20 days of 90+ degree heat. Cool-season turf, especially poa annua, really begins to struggle when soil temperatures consistently hit 90℉. Because of the abundant amount of shade due to the high number of trees the playing surfaces have a considerable amount of this cool-season turfgrass variety.
• It rained-ALOT! WHCC received over 6" of rain for the month of July. And we went through an 8 day period from July 14th to July 21st where we experienced 3.48" of rain falling. This kept the turf consistently wet that was preceded and followed by heat waves of 90+ degree temperatures. Click here for the July Cincinnati weather data.
• The saturated soils from pop up thunderstorms were quickly followed by the hot July sun. This led to sunscald and wet wilt (see below) that literally boiled many areas on the course. Especially low lying fairway locations.
• Unlike the tees and greens that have a sand cap or sand base, the fairway soil is comprised of a typical Western Hills soil profile of limestone clay. This prohibits the water percolating through the root zone and keeps water at the surface for longer periods of time. This combined with the short cut turf covered the grass with water in many locations leading to "boiling" conditions once the sun appeared.
• Transpirational cooling is being prohibited by hot night time temperatures. Usually the grass plant can recover a bit at night, but the abundant amount of moisture near the surface, from the hot and humid nighttime weather, prohibits the plant from transpiring to cool itself off. When this stressor continues for hours and then days turf begins to decline. Cincinnati actually set a record for the month with 23 nights at or above 70 degrees.
• The consistent wet weather occurred at a time when our spray applications need to be applied at the correct intervals. It was a struggle to spray surfaces with the busy golf calendar and the unpredictable pop up storms. Eventually we had to become aggressive and apply fungicides with only small windows of dry time. This most certainly decreased the efficacy of the treatments allowing possible breakthroughs of summer time diseases that thrive in hot and moist conditions.

All these factors came together to produce dying turf on many playing surfaces. So far the fairways have taken the brunt of it, with more dead patches here than other areas. Ask any turfgrass professional in this area about the worst conditions to grow cool-season grass and I guarantee wet, hot, and humid will top the list. Hot and dry conditions are tough as well; however, moisture can be supplemented and the grass can go into a dormant state increasing survival chances. This is not the case in wet and hot situations. The turfgrass does not have any natural defenses and if stressed enough, for long enough, will die.

We are still in the midst of this hot and wet stretch and will not know the extent of the damage until cooler temperatures arrive. However, here is a list of solutions we have implemented or will begin to implement to help with recovery. Click here to read a USGA article on this seasons turf decline.

• Raising mowing heights. This will help to decrease stress on the turf and allow more leaf surface to aid in transpiration and photosynthesis.
• Venting low lying fairway areas with 1/4" solid tines. This will help open up the soil surfaces allowing oxygen to reach the roots.
• Slit seeding dead fairway patches. This has taken place in some areas; however, the bulk of it will have to be accomplished when weather becomes more conducive for germination.
• Adding drainage to low lying fairway locations. There is an abundant amount of drainage in many of these areas that we have installed over the years. Some locations (15 valley) may need more drainage added.
• Judicious watering. This might sound a bit odd given the really wet conditions, but the turf's root system has shortened because of the abundant amount of moisture. A couple days of high ET rates and the top 2-3" of soil will be dry. Water is needed to keep the stressors down and the turf alive.
• In the short term we will be more aggressive on cart limitations. Rough day and cart path day will have to become more common until the weather improves to limit damage to already stressed turf.

A quick drawing of how water flows into #15 valley. It is easy to see why this area has always been an issue during wet, hot weather.

Wilfredo slit seeding #15 valley. Hopefully we will get some germination

Topdressing, venting, fertilizing, and filling in divots at the south tee.

Slit seeding the south tee. In addition to the rough weather, the tremendous amount of play this tee received during July increased turf stress.

The tee a couple days after maintenance performed. It is starting to heal.

Wet Wilt 

Wet wilt occurs when very high soil temperatures and low oxygen levels (because of the wet soil) cause the impairment of root function. This causes the roots of the turf (especially poa annua) to slow down water intake decreasing the transpirational cooling that the plant needs to survive. Hot and humid night time temperatures increases the severity of this condition. Hot nights (70 degrees and above) plus wet soil increases root respiration stress decreasing plant oxygen uptake. Thus, on hot days and hot nights with high evaporation rates the turf begins to overheat, wilt and die, despite having adequate moisture in the ground. This is the most common condition affecting the fairway turf this summer season. 

.

Wet wilt damage at the bottom of #15 valley.

Robotic Mower

A Husqvarna 535 AWD solar powered robotic mower has been installed to mow the north practice tee surrounds. This unit can mow up to an acre and is able to handle inclines of up to 70%. This is a test mower to figure out if robotic mowers (and eventually a robotic ball picker) can be utilized to maintain the driving range complex. These mowers come with significant benefits including lower prices than the riding mowers, decreased labor hours, zero gasoline emissions, and the ability to mow 24/7. So far this mower has worked well. The only issue we are having is the battery is unable to keep a full charge during long periods of cloudy weather. This is a problem more with solar power in general and will not affect any future mowers installed using electricity. Obviously, there will be some significant cost if electricity is run out to the driving range area, but we will continue to work with the green committee and vendors to see if this will one day be the solution to the driving range maintenance issues. In the meantime please be respectful when seeing this mower out doing its job. Although cheaper than the gas powered rough units, it is still a unit that will be expensive to replace if it is run over by a cart or continually hit with golf balls.

Robotic mower and charging station.

Bees in Bunkers

Over the last couple of years small wasps have begun to buzz around some sand bunkers. They are smaller than the usual suspect, the cicada killer wasp, but tend to look almost identical. These are sand wasps (Bicyrtes quadrifasciatus). Joe Boggs, Ohio State Extension entomologist, wrote an article about these wasps a couple years ago when he found them at White Oak Garden Center (click here for the article). They feed off of brown marmorated stink bugs and are also named stink bug hunters. Like cicada killers, they are solitary wasps that are not aggressive and rarely sting. They dig burrows into sandy soils, making bunkers a perfect environment. Chemical control is difficult because the wasps are scattered out into many different burrow colonies. Daily raking of the bunkers helps to keep the populations down, but the wasps are extremely difficult to fully eliminate. We have made some pesticide applications; however, they eventually resurface. Sand wasps are technically a beneficial insect, and are not a threat to stinging humans. We will continue to frequently rake the sand traps, and if this year is similar to the past, they will eventually move on. Click here for a USGA article on these wasps!

Finally, I ask everyone to please be respectful to grounds workers if you run into them during your round. The summertime heat is not only affecting the turf but the workers as well. Many of them are working 55+ hours a week in 90+ degree heat to try and keep the golf course playable. We start work at 5 am to try and stay away from play, but shotgun starts and the busy golf calendar make worker and golfer interactions inevitable. Please treat any inconvenient interaction with the hard working agronomy team with courtesy and respect, remembering the golden rule, "do to others what you would have them do to you." Here are some USGA videos on Etiquette towards maintenance personal.

USGA Course Care: Etiquette towards maintenance personal

Up Before the Sun: Getting a Golf Course Ready for Play

I remain optimistic (gulp) that this monsoon heat wave will end soon. In the meantime the agronomy team will continue to battle the conditions to keep the course in the best shape possible. Fall can't get here soon enough!

Brad Piecuch

Grounds Superintendent