Bentgrass Bounce Back

If you recall, last week we were staring at some fairways that had gotten pretty banged-up from aerification.  As a reminder, here's what #5 looked like at the time:

While the irrigation system allows us to get by for a while, there is no substitute for the uniformity we got from the steady rain earlier in the week.  Additionally, going from high temperatures in the 90s, to the 70s makes a world of difference in turf recovery.  #5 fairway looks just a little different now than it did a week prior:

Looking ahead, there are no days forecast to be in the 90s.  This summer was just plain tough on the turf, so let's hope the weather prognosticators are correct!

This actually helps the turf?

In looking at the fairways immediately following this past week's aerification, it certainly doesn't appear that we were trying to improve course conditions and turf health.  By the time we got to #5 on Monday, the 90+ degree temperature and low humidity that day had things drying out extremely fast, causing turf to wilt.

You can see that the small skips between aerifier passes actually look much healthier than the surfaces where plugs were pulled.  So why do we put these low mow turf areas through such torture--you have to wonder, is the juice really worth the squeeze?

It's during times like this that you need to take a step back and keep in mind that aerification is like major surgery to a person.  The long-term benefits--in this case decreased organic matter and compaction, increased pore space and percolation rate--far outweigh the short-term stress that this procedure causes.

Would this aerification be advisable under all circumstances? Probably not, but fortunately Laurel Creek's 35 year old fairways are still virtually Poa annua free, and the Bentgrass will bounce back.  Had this been a stand of Poa, we very well may have been ordering a few bags of seed or pallets of sod to restore these areas.

Looking at the low...

While we are now back in the oven with temperatures in the 90s during heat wave number six, last week provided a welcomed respite from this tough summer weather.   Most of us focus on these daily high temperatures, however the nighttime lows can be equally important to the turf.  

Below is a chart showing the temperatures of #1 green at a 2" soil depth from the end of July through the first week of August.  Suffice it to say that when the "coolest" the rootzone gets is 80 degrees at night, there is pretty much zero chance of any recovery from the daytime heat.

In contrast to the end of July, the beginning of August actually had some daytime high soil temps peak at around 80 degrees, accompanied by much cooler nighttime low temperatures in the 60s.  This may have been just a quick break for the turf, but we will take it.

Lesson learned...

July is already the hottest month of the year, so when you have 21 days in that month that are above average, it shouldn't come as a surprise that our cool-season grass isn't going to be happy.  The green which has seen the most thinning turf over this stretch has been the practice green at #1 tee. 

For decades the USGA has said that building a new green without changing the environmental conditions is not a recipe for success.  In the case of the driving range putting green, not only have the growing conditions not improved, but they have actually taken a couple of steps backwards.  

As you may recall, we had a permanent fan for the old green, and with additional wetlands growth every year, there is even less air movement and morning sunlight than we used to have a few years ago.  In hindsight, it was probably naive to think that just constructing a larger green would lead to healthy turf without the benefits that its predecessor enjoyed. 

For now we are using our portable fan to provide air movement on the green, and have closed a portion of the green to help facilitate recovery.  In the long run we clearly need to install the dedicated fan for this green, as well as try to do some selective pruning.