Bermuda grass incursion on putting greens

You may have noticed that we have some Bermuda grass that has grown its way onto the putting greens. At this time of year it is especially noticeable. While it isn’t an immediate threat to the putting greens, it is concern we will address.

We have several tactics to deploy against the Bermuda grass. However, everyone must remember two important things: 1. Bermuda grass is almost 100% indestructible. It can be severely retarded and even killed down to the very deepest roots, but it will ultimately come back; 2. We are in no danger of Bermuda grass becoming the dominant turf grass on the surface of the putting greens. The putting green maintenance, combined with the weather is far too harsh for the Bermuda grass to tolerate.

Same photo as one to the left. The red line marks
the edge between ryegrass collar and
Bermuda grass approach. The Bermuda grass has moved
from the approach into the collar.

Now, we need to clarify that there are two separate circumstances related to Bermuda grass creeping towards, and sometimes onto the greens. First, there is the Bermuda grass that is coming from the approaches where Master Plan work has been completed and Bermuda grass sod was laid. This is Riviera Bermuda grass and is the same variety as the fairways and new tees. However, this is not the Bermuda grass that is creeping onto the greens. This Riviera Bermuda grass is moving in lots of directions, including towards the greens, but it has not reached yet, and we are working on keeping it away. Everywhere there is Bermuda grass that has reached the putting surface is a different scenario.

This second scenario is a completely different variety of Bermuda grass. It is a common Bermuda grass and has probably been on Bretton Woods property for many years, even probably prior to any Bermuda grass being seeded in the fairways. It takes a significant hit every winter and then coupled with the greens maintenance program, it has taken a very long time to reach the greens. But it had already reached the greens for at least the past 3 years (my tenure) and probably back into Bryan's time as superintendent as well. This past summer was a tremendous summer for Bermuda grass, so it reached in farther than it had in the past and was thus more noticeable, but it did not accomplish all of this solely this year.

Same photo as one to the left.
The red line marks the edge between ryegrass
collar and the putting green. The
Bermuda grass has moved from the collar
to the green.

Both situations are issues, and we are working on, or have developed a plan, to tackle each problem. The Riviera Bermuda grass that is moving in from the approaches is being dealt with in two ways. First, this past week, we seeded Bermuda grass spots in the collars with ryegrass. The seeder is 5 feet wide so only areas where we could fit the machine in were done, but we made passes straight across nearly every approach to sharpen the line between collar and approach. This is the first time we have tried this and the results will take time and even then may not be enough. So, we are also formulating a plan to sod out the Bermuda grass from the collars. This is the plan for the very narrow areas of collar where the seeder will not work. Our first step will be to salvage the ryegrass from the large approaches on 11 and 13 next year during construction. We will then replace Bermuda grass in collars with this sod. This will not complete all of the necessary areas though. Next, since ryegrass sod is not readily available for purchase, the plan is to use Kentucky bluegrass sod, which looks very similar, and then seed ryegrass directly into the sod. Using sod will give the instant completion, but Kentucky bluegrass does not perform very well in this region, so we will immediately get ryegrass seed in as well. If the seeding we did does not perform well enough, we will sod some of those areas as well by the same process. Sod work that is not completed using repurposed grass from holes 11 and 13 will wait until the fall of 2017 and beyond.

Same photo as one to the left. The red circle
shows where the Bermuda grass that is currently
in the collar originated. The Bermuda
grass started in the rough and did not
come from any sod associated with
the Master Plan.

Our more immediate tactic for targeting the Bermuda grass that has actually made it onto the putting surfaces will be in progress over the next few weeks. We will be physically cutting and removing the Bermuda grass that has stretched onto the greens. We waited until now because we want to use the cold weather to our advantage. In the summer, we cut (verticut) the Bermuda grass to invigorate its growth and doing the same thing in the cold weather will either entice the Bermuda grass to try and grow or leave it vulnerable to damage from cold temperatures. Either way, the Bermuda grass is injured significantly, possibly even more so as winter wears on, and thus set back next year. We will fill in the voids with a mix of sand and bentgrass seed. Again, we will not be able to remove all of the Bermuda grass, but what we don't remove is hopefully stunted next year, and what we can remove is replaced with bentgrass.

Unfortunately, there is no curtain that will entirely prohibit Bermuda grass from moving in different directions. This will be an ongoing issue that we have to manage. However, we do expect to be able to manage the issue as we move forward.

Etiquette Reminder of the Month

Winter cart path rules are now in effect in order to protect the dormant Bermuda grass.

See you on the course!

Joe

jvillegas@bwrc.org