Sunny Side Up Please

Growing grass, on it's most basic concept, is a pretty simple formula.  All you have to do is throw in some food, add some water and give the plant lots of sunshine.  If you have all of the those things in abundance the plant will go bananas and grow literally like a weed!  The problem with that formula on a golf course is that there's always a limiting factor.  It could be not enough food or an imbalance of the right foods, it could be not enough or too much water and sometimes its not enough sunshine.

When you do not get enough sunshine on our warm season grasses they do not perform very well.  Warm season grasses need a minimum of 8 hours of high intensity sunlight to survive, but really likes about 13 hours of intense sunlight.  Notice I didn't say 8 hours of sunlight equals "super awesome."  The challenge for golf course superintendents down here is trying to get "super awesome" during the winter months when temperatures and light intensity are at their lowest points.  I am trying to get the golf course to be super awesome during the times when all the factors are against me.  This is completely opposite of what happens during the golf season up north.  The golf courses up north are more or less only open when the grass is actively growing and the conditions are favorable for "super awesome."

One of the first things that happens to bermuda grass when it doesn't get enough sun is that it thins out.  In this picture of 14 green is a typical scenario played out caused by shade issues.  First comes the thinning out, then the algae sets in and then complete loss of turf.

In this picture you can see what time it is and where the shade line is compared to the red circle indicating the trouble spot.  The part of the green on the right side doesn't have any thin areas.  This green is heavily shaded from early morning sun compared to 18 green which has had full sun since 7.  Sometimes an extra hour is difference between healthy, thick turf and a sod cutter.

If there is a shade issue on a course, it's going to happen every year at this time.  The shaded grass on the putting surfaces are starting to get tired from having to use all of its carbohydrate reserves (stored food) in it's root system because there's not enough sun to produce all that it needs.  Because the sun is so low in the sky and the intense light duration is limited, the grass will literally burn itself out trying to survive.

I took this picture with my IPhone using a program called Sun Seeker.  Sun Seeker tracks the movement of the sun.  The yellow line represents today's sun path, the blue line represents the lowest angle of the sun in the dead of winter.  This should help illustrate what I mean by sun intensity.  We all know the most intense sun is in the summer.  It's the most intense because the sun it the highest in the sky, almost directly overhead.  The good news is the days are getting longer and the sun is slowly getting higher everyday.

This picture was taken looking straight up into the sky over 14 green.  The top of the picture is pointing north and the bottom is facing south.  I wanted to show you how much more the sun has to climb into the sky before it is at it's peak, where the sunlight intensity will be at it's highest.  The yellow line is today's sun pattern and the red line is the summer solstice.  Remember the higher in the sky, the more intense.  Notice the dates.

Another important angle to look at is where the sun is compared to time of day.  There's an old wife's tale about morning sun is better than afternoon or vice versa, in reality what's important is simply how long do you get sun.  Some plants have a larger light requirement than others.  Putting surfaces have a huge light requirement.  The reason has to do with the height of cut.  Our putting surfaces are cut down to almost 1/10 of an inch.  That doesn't leave much leaf surface area to capture sunlight to be converted into energy for the plant.  Simply put, the lower the height of cut, the more sunlight is needed to preserve health.  An old superintendent's trick when we've had several days of cloudy,  or not so sunny days is to raise to height of cut to give the plant just a little extra leaf surface to capture a smidgen more sunlight.  REMEMBER, LEAVES ARE THE PLANT'S SOLAR PANELS.  THE MORE SOLAR PANEL SURFACE AREA YOU HAVE THE MORE ENERGY CAN BE PRODUCED!

Shade on a green is not necessarily a bad thing.  In fact, shadows are a very distinct design feature architects use to create eye movement and character to a golf course landscape.  Like most things in life, it all comes down to intensity and duration.  The trick in managing a healthy turf is to be able to balance both intensity and duration, too much of a good thing can be detrimental too.