Monday, 15 August 2011

Greenspeed, Rolling and Height of Cut....the Relationship.

It is easy to get used to a particular way of doing things.  For years we at our course have cut the greens daily during the growing season.  This was just the way we did things.  We felt that this was the best way to provide smooth consistent playing conditions on our putting greens.  For the most part this statement was true.  Two years ago we purchased a roller for our greens.  Most of the literature I had read warned that rolling the greens too frequently lead to compaction and wear damage on the green collars.  It suggested that greens be rolled a maximum of 4 times a week.  Other articles suggested that adequate green speeds could be achieved if you cut at a higher than normal height and rolled more often.  So this is what we did........because that was just the way it was done.....

We had our greens mower set at a bench height of 0.125" and we rolled 4 times a week.  Green speeds averaged 7-8' on the STIMP meter.  This sucked!

So I tried rolling more.  We rolled 6-7 times a week and then saw speed rise to maybe 9' max.  Ok but not quite there.  I also didn't see any of this compaction or wear damage that everyone warned about.  NONE! But no matter how often I rolled I just couldn't get the speed up past 9'.

So last week I come across an article by Greg Evans called "Wuthering Heights"http://www.gregevansmg.co.uk/greenside.php .
He made a very convincing argument why green heights could safely go lower.  My greens were in great shape and I was bored so I though, "why not??"

So I dropped my bench height down to 0.110".  I didn't want to go crazy just yet.  So I went out and cut my greens then got out the good old STIMP meter.  They clocked in at just shy of 8.5'. whoopeee.  So I thought maybe I'll try giving them a roll.  Rolled and STIMPed again.  BOOM!!  10'!!

So even though the height of cut was lower, the green speed weren't significantly different than the previous HOC. But the lower HOC combined with rolling gave me the speeds I wanted.

So then I tried only rolling.  Speeds were at 9.5' on the STIMP meter.  This wasn't significantly different from the cut and roll that I did the day earlier.  According the the USGA, the average golfer can't tell the difference of a foot on the STIMP meter.

So now I'm thinking "why am I cutting seven days a week?"  If I can cut four times a week and still achieve the same consistency and speed why not?

This lead me to think that the HOC on the greens only offers the potential of a high STIMP reading.  Rolling brings out the potential.

So this week I am only going to cut my greens 4 times.  I will roll every day.  Each day I will take a reading before and after I roll and compare the two.  So far, after rolling I am seeing a jump of approx 1.5' on the STIMP meter.

Cutting the greens causes stress.  It probably causes more stress than rolling.  I don't know this for sure because I'm not a scientist.  But if I'm right, my greens will be faster and healthier if I only cut 4 times a week and roll 7!

Furthermore, the cost of purchase and maintenance is much higher for a greens mower than a roller so rolling more and cutting less should save money in maintenance.

Have some fun and reverse the frequency that you cut and roll and give it a try.  What have you got to lose??

EDIT:
So here is my graph in progress comparing the green speed to the different rolling and mowing practices this week.  This is an interactive graph and will be updated in real-time as I collect the data so check back daily.