As spring time nears, we start preparing for summer. Not necessarily about warm days by the swimming pool or trips to the beach, but about a subject we all wish we could avoid, summer transition.
To have a successful summer transition we must begin by lowering the mowing heights in early February. This allows for sunlight to penetrate the grass canopy of the waking Bermuda grass. Without this step the Bermuda will die and create serious issues in the late spring.
This year we will address the summer transition in a slightly different manner than last year. A year ago we sprayed out the rye grass with a herbicide that literally took out the winter rye grass in a matter of days. This eliminated the competition and allowed the summer Bermuda grass to take over and by mid June we were 100 percent Bermuda grass. However this method creates six weeks of less than desirable conditions.
This year we will use a different herbicide that will gradually remove the winter rye grass. The herbicide will be applied in three segments three weeks apart. This will slow the growth of the rye grass while the Bermuda grass begins stretching its legs as it is coming out of dormancy. We will do the first application in early April.
I attended an Arizona Golf Course Superintendent’s meeting last week to discuss the latest and greatest practices and methods for a quick and smooth summer transition. In attendance were golf course superintendents from Desert Mountain GC, Desert Highlands GC, Arizona CC, Paradise Valley CC, Anthem CC, and Wickenburg Ranch GC just to name a few. With over 40 golf course superintendents sharing ideas and experiences, it was without question we all had the same goal in mind. To transition our golf courses as quickly and as smoothly as possible. I learned that different courses use different methods such as choice of herbicide for removing the rye grass, timing of the herbicide application, over seed rates, rye grass variety, and fertilizer applications. The other thing we all agreed on was that there is not a one size fits all solution. Budget sizes, Bermuda grass type, water quality, and soil types were all over the board. Some courses had the resources to do what others could not.
One other thing we agreed on was that Mother Nature calls the shots. Early April is usually the most favorable time to apply the transition herbicide, but not every April is the same. If the temperatures are too cold, the herbicide will damage the winter rye before the Bermuda grass is ready to come out of dormancy. We have seen frost in April before. No two years are alike.
Some golf courses choose to avoid spraying out their rye grass. These courses will look great in the months of May and June, but will pay dearly July through September for not doing so. Then without a healthy Bermuda base, their next overseed is usually a struggle. A healthy summer transition is what creates the base layer for a successful overseed the following year.
This picture shows how Bermuda grass dies if the ryegrass is kept well into the summer.
The other key component to a successful and quick transition is the monsoons. Without rain and clouds, transition is slower and the process is longer. Bermuda grass loves humidity. Without humidity, Bermuda grass will drag its feet and take longer to recover from dormancy. This is why it is very important that we irrigate heavy during the transition period. This process although not as effective as the monsoon humidity keeps the Bermuda grass moving.
I hope this information was helpful in better understanding the summer transition process. We will continue to work towards the best possible method to get our courses to convert from one crop to another with the least amount of disruption.
Rick Walker - Greens Chairman
David Escobedo GCS