If you’ve been on the course in the past week, there’s a really good chance you’ve noticed a lot of bleached white turf, specifically around greens and on bunker faces. This is completely intentional.
The definition of a weed is a plant out of place. In this case, Bentgrass growing in the rough, is a weed. We love Bentgrass, and most of our cultural and agronomic program is to promote it. However, we only want it on Tees, Fairways and Greens. Everywhere else, it’s a weed.
In the Fall of 2023, we did a large test trial around 5 green and its bunkers, as well as to the right of 14 and 17 fairways. The trial was to familiarize ourselves with a selective herbicide that removes Bentgrass from the rough, while being safe on the desirable grasses. It must be applied every 2 weeks for 3 applications, and seeding new desirable grasses into the dying Bentgrass can occur after the second application of herbicide. Timing of the herbicide (Fall) has more to do with germinating new grasses effectively, with the highest chances of establishment, than anything else.
To read about last years trial, and the initial explanation of the process, click the the following links:
https://www.mhccturf.com/?p=3047
https://www.mhccturf.com/?p=3088
After a successful trial in 2023, it was approved to move forward with a large scale plan in 2024. This Fall, we’ve treated all green surrounds, as well as bunker faces. Logistically, we can only tackle so many acres at a time. The laborous part of the process isn’t making the application, it’s reseeding the dying Bentrass patches. The dangerous part is making sure the chemistry isn’t drug onto the playing surfaces from member or staff cart tires, as well foot traffic. As you can imagine the consequences of that, we avoid even that possibility, by making the applications at strategic times so that the chemistry is dry by the time traffic reaches it.
The following maps outline where the applications were made. As you can see, after treatment, we had a relatively small % of Bentgrass in the treated areas.
As of today, all of the green surrounds have already been reseeded. The bunker faces have to wait another ~2 weeks as the herbicide is harsh on Fine Fescue establishment, preventing up to 35% germination. The downside is that our bunker faces are predominantly Fine Fescue and a few bunkers specifically have the most % of Bentgrass in them anywhere on the course.
So the bunkers will look like spotted cows for another few weeks, until we seed them. That process will involve literally climbing on the bunker faces, seeding the spots by hand, and topping them off with a thin layer of soil. Our goal is to have all of the bunker faces seeded by the end of September. Once you see that the white spots of the cow have turned to a black color, please refrain from hitting shots off them, or walking through them. You should never be walking on the bunker faces anyway, so this is just another reason to stay off them 🙂
So why do we have so much Bentgrass on bunker faces and green surrounds? As I explained in the previous posts, Bentgrass migrates for several reasons. First through seed in divot mix getting washed away from its intended target. Secondly, decades ago, cores used to be taken out of playing surfaces, drug around to knock the soil off, and the plugs got blown into the rough throughout the golf course. Those cores then established in the rough. Lastly, Creeping Bentgrass CREEPS. It grows laterally above ground through stolons. If Bentgrass is healthy, it will spread. It’s healthy because the growing conditions for it are ideal, and/or it doesn’t have solid competition. In the case of our bunker faces, the Fine Fescue cannot outcompete the Bentgrass in certain scenarios. Because we mow our bunker faces so tightly, it gives the Bentgrass a competitive advantage.
Am I saying we’ll always have Bentgrass in our bunker faces? Yep. Everything good comes with a cost. The cost of having bunker faces that don’t stop balls from rolling off greens, and release golf balls down into the bunker sand, is a tradeoff. Will we have to treat them every year? No. We’ll always have Bentrass in the roughs. But we want to have the % be in the single digits, so if we do treat again, its minor impact.
We are only treating around greens and bunkers this Fall. Next year, if the weather looks cooperative, we’ll move onto the next features of the course. Will we get a perfect catch on seeding, and everything comes back perfectly this Fall? No. We’ll stay persistent with the seeding and reestablishment of desirable grasses until we’ve been 100% successful.
Thanks for the patience and support as we make this change over. It will give you the most ideal playing conditions in the future. Thanks also for not accepting status quo. We will continue to make improvements to the golf course and infrastructures in many areas, some very noticeable like removing the Bentgrass in the rough, to some that are much more stealth, like a large drainage plan we have for the 17th fairway later this year. Through all of them, we need support, embracing that we will not be happy with just doing what we did yesterday. Tomorrow, we’ll do it better.
Mike Manthey
Thanks for another great turf blog!