Population Shift

Laurel Creek's putting greens are comprised of two very different grasses, Poa annua, and Creeping Bentgrass.  One of the challenges this presents, is trying to insure a smooth putting surface, when the growth habits of Poa and Bent do not coincide.

In our region, Poa can outcompete Bent for most of the year, but then the summer heat comes, and Poa is not a happy camper.  It is always interesting to see how the percentage of these grasses in the greens appears to shift from one season to the next.

As you can see in the picture below, the Bentgrass in the center is coming on strong, while the Poa isn't a fan of July's weather.  There certainly appears to be more Bent than Poa here.

This is quite different than what we see in the spring, where Poa is growing like crazy, and controlling its seedheads is of utmost importance.  An untreated check plot from a seedhead prevention spray shows a whole lot of Poa, and not so much Bentgrass at that time of year.

Below is one final picture which illustrates the competitive edge which Bentgrass has now.  In the areas where we had Fairy Ring hit hard a few weeks ago, it's the Bent that's moving into the ring's perimeter.

We have now past the peak for average summer high temperatures, going from 87 last week, to 86 degrees this week.  While August typically means the shortest roots of the year for cool-season turf, it's good to know that the thermometer should be heading in the right direction, giving both Poa and Bent a much needed break.

Growing some good weed

Hang on  a second--before anybody gets the wrong idea, we are not talking about a potential new revenue stream for the golf course.  No, in this case, the "weed" we are referring to is milkweed.

The monarch butterfly population has declined dramatically during the past 20 years.  These beautiful insects are dependent on milkweed, and out of play areas on golf courses can provide a great habitat for this plant, and the butterflies.

As a Certified Audubon Cooperative Sanctuary, Laurel Creek is committed to managing the course in an environmentally sensitive manner.  Therefore, when Audubon International established their "Monarchs in the Rough" program, the decision to join was an easy one.  Assistant Superintendent, Don Holgersen, continues to do a great job in keeping us involved in programs such as this.

So, yes, while milkweed may have that four letter word (weed) in its name, it is an important, beneficial plant.  Based on what we are seeing thus far on the course, it's definitely being appreciated by the monarchs!

Goldilocks Time

If you play the course early in the day, and think the fairways are soft, they very well may be.  When we go through periods that require us to rely exclusively on the irrigation system, moisture uniformity is difficult to achieve, often leaving some areas too firm (aka, dry), and others on the softer side.


There are several factors which contribute to consistent moisture levels--or lack thereof.  For example, the soils on the golf course are quite varied, ranging from fast-draining gravel, to dense clay.  The golf course's topography also leads to exposed mounds drying more quickly than their surrounding swales.  However, probably the single greatest factor impacting moisture uniformity is the irrigation system.

Laurel Creek's irrigation system was designed in the 1980's, and has sprinklers spaced 80' apart.  That is a good chunk of land for a head to cover, and conditions can differ greatly within that area.  Generally speaking, irrigation systems in our region work well to supplement rainfall, not replace it.

In the picture below, you can see some pretty dry turf only 20-30' from the closest sprinkler.


Given the limitations of the system, it will take a full eight hour irrigation cycle to run greens, tees, fairways, and the primary rough for an average of just 15 minutes per sprinkler.  At this time of year, with moisture loss around .25" per day, we are operating in a deficit irrigation mode.  That is, even when running a full cycle, we are not replacing all of the water lost each day.

Where sprinkler coverage is incomplete, portable roller base sprinklers are used to supplement.

Hand watering is another primary way we target specific areas without running the irrigation system excessively.  It is not unusual for us to devote over 1,000 man hours in a season to hand watering.

Without question, water management is one of the most challenging parts of properly maintaining the golf course right now.  Too much water is not good for plant health or playability, and too little water can obviously have its consequences as well.  While this may lead to that Goldilocks feeling (it's too wet here, it's too dry there), the good news is that sooner or later the heat will break and the rain will come.

It's always something...

As we worked through the heat wave last week, overall, it looked like the course was holding up well.  Of course, that would be the time that some Fairy Ring disease came roaring in on several of the greens.  When Fairy Ring shows up, there is no need for a petri dish and microscope to diagnose the problem, as this fungus is quite easily identifiable.

There can be several visible signs of the fungi at work:  a dark green circle caused by a release of nitrogen in the soil, mushrooms may form on the turf surface, or the fungi may cause the perimeter of the ring to become hydrophobic, causing the turf to wilt. 

Moisture level on the edge of the Fairy Ring.

Significantly higher moisture inside the ring.

A combination of fungicides and wetting agents labeled for the control of this fungus have been applied.  However, these rings are persistent, and with the low fertility regimen we have the greens on, the rings really stand out.  The pictures above were taken the day after treatment, and the "10.3" reading is actually an improvement, and encouraging.

We always try to look ahead, and have an idea of what may be a potential issue.  So, why did the Fairy Ring come as a bit of a surprise?  Well, in looking at our application records, it has been six years since we have had a problem with Fairy Ring.

In trying to better prepare for the future, it would be great to have a solid disease prediction model for Fairy Ring.  One thing that jumps out between the past two times we have seen the disease are temperatures.  When you look at the end of June and beginning of July, 2012, the conditions parallel what we have experienced this year--some really hot, humid weather.  It was the exact same time frame when we last saw Fairy Ring, in 2012.

July, 2012, started out hot!

While it's never fun dealing with these issues, it's somewhat consoling to know we're not in this alone.  A local turf industry consultant recently said that he has seen more Fairy Ring in the past 10 days than in the past three years.  This picture (from a different course) is definitely impressive:

We certainly won't shed a tear if we don't see Fairy Ring again until 2024, and thanks to some experience and solid record-keeping, we should be better prepared when it does arrive.

Time to play some defense...

For those that grow grass which is cut as low as 1/10", and has to endure a whole lot of traffic daily, we are in the midst of a stretch of nasty weather.  With the exception of the lower practice tee, all of the turf on the golf course is considered to be "cool-season" grass, and the temperatures outside are anything but cool right now.

Up until this point in the season, we have easily been able to push conditions without much concern.  Double mowing greens and rolling several days each week have been standard practice.  However, now it's time to back off--just a bit.  We will continue to mow greens each and every day at the same height of cut, but until the heat breaks, we won't add the additional stress of a second mow, or putting the roller on the greens.  Any mechanical injury caused at this time, will be very difficult for the turf to recover from.

What else do we do when the seven day forecast shows nothing but 90's with some really high humidity?   We definitely apply plant protectants preventatively to the greens, tees, and fairways.  This weather is perfect for some turf diseases like Pythium blight, which can do a whole lot of damage in a hurry.

Another real challenge now is water management on the golf course.  As a whole, we saw quite a bit of rain during the month of June.  However, 85% of that rain came in the first 10 days of the month, and things have been more "miss" than "hit" since then.  When relying on the irrigation system, we don't have the same coverage uniformity that rain provides.  With this really hot and sticky weather, too much water can be worse for the grass than too little water.

It was a cool spring, with many people asking, "When is it going to warm up?"  Hmm, perhaps we should be careful what we wish for!