So, you went ahead and did it! After all the talk and hyperbole about saving money and doing what was right for the environment and the industry, you did it anyway. You overseeded because you didn’t want to be the course down the road that looked dead in the winter. You overseeded because your particular group of golfers wanted to play on green grass and you didn’t want even one greens fee to go to the course across the street. It’s OK, I overseeded, too!
So, now the question is, “what do we expect during the transition period?”
That is the question every superintendent and every golfer in the southern parts of the state are asking. Unfortunately, transition is not a specific date, nor is it a reference to a particular event. It is merely a time when the overseeded winter grasses, e.g. ryegrass, poa trivialis, bentgrass, give way to the warm season turfgrasses that predominate in hot, humid conditions. Remember, when the seed bed was carefully prepared for overseeding last fall?
Scalping the turf, verticutting and spring raking took out the Bermuda that was just at its’ peak time of year. Robbed of its’ opportunity to store reserves and harden off as the winter temperatures approached, the little Bermuda that survived was sprayed with growth regulators to keep it from competing with that cool season species that everyone was trying to promote. The final result is a very confused warm season species that must be saying, “do you want me here or not?”
The little Bermuda that survived was sprayed with growth regulators to keep it from competing with the cool season species that everyone was trying to promote. The final result is a very confused warm season species that must be saying, “do you want me here or not?”
Along comes spring with the ever increasing daylight hours and the subsequent warm nighttime and daytime temperatures. The areas that were not overseeded start to green up and enjoy the warmth of the spring. However, in areas that were overseeded there is a stiff competition for space, light, oxygen, nutrients and water. Depending on several agronomic factors, e.g. site, slope, compaction, etc., one or the other species outperforms the other and the resulting golfing conditions can be somewhat erratic.
Remember, when I said that this transition is not a specific time or place? There must be a culmination of several factors; nighttime temperatures, length of day, humidity … and no single one can be missing to effect this desired transition. Golf Course Superintendents have tried for years to predict this time with little success. More recent innovations, such as turf growth regulators and herbicides, have made it more manageable, but these often can be accompanied by negative side effects.
If there is one surefire way to stimulate transition, I don’t know it. Greater minds than mine have tried numerous techniques. There are those that go after the cool season species very aggressively with a combination of chemical and mechanical means, along with reduced irrigation applications. This has been very effective at courses where this time of year is clearly identified and the public is aware that the attendant golfing conditions will reflect this effort. There are other equally intelligent superintendents who try to let the process happen as it may and to supplement the processes of time with light, but frequent, verticutting and aerification. The risk there is that when the conditions become right, that ryegrass is going to check out no matter what you do and if you haven’t created an environment conducive to healthy Bermuda then you are stuck with nothing until such time as the Bermuda wakes up and starts to move on its’ own.
Bottom line to the golfing public, this is a very difficult time of year. Conditions will generally stay good right up to Memorial Day. Modern sophisticated irrigation systems, along with adequate drainage systems, can keep cool season turf active and growing through warm daytime temperatures in the absence of humidity. In June, when daytime temperatures are reaching 110 degrees some afternoons, that ryegrass will start to lose its’ root system and the water it will be able to get will be surface water. It will green up every night and wilt every day. Playing conditions will be wet in the mornings and parched in the afternoons. All this while your superintendent will be aerating fairways all turfed areas with an eye toward moisture retention, because Bermuda will grow virtually anywhere you can achieve moisture retention. Efforts will be made to treat thinly turfed areas by sprigging, seeding or sodding, but none of these will be thoroughly effective because there is still no humidity. Transition truly arrives on that day when the plant can no longer cool the canopy and the temperature in that zone increases by sixty degrees overnight. That’s the day that the cool season species checks out of the golf course hotel.
In conclusion, we are all reaping the consequences of that decision we made last fall. When we decided to overseed, we accepted these transitional challenges and all the inconveniences that accompany them. We decided that our playing conditions for a few months in the winter was worth sacrificing part of this spring and summer. Agronomically, overseeding, is the single most important force motivating everything else we do throughout the year. Basically, we are looking for 100 days of good Bermuda growing weather to get that species back into shape so we can start all over again this fall. We never, as turf managers, have time to develop anything or build on last years’ success. Caught in the death spiral with no way out.