Early Overseed Transitioning

While many golf facilities have moved away from winter overseeding in the Florida Region, it is still a practice that some courses conduct to improve turf color. Transitioning from perennial ryegrass back to the base bermudagrass takes place each spring and is usually just beginning at this time. Given warmer than usual temperatures this spring many courses in our region are reporting the transition is well ahead of schedule as it began over a month ago. 

Some golf courses are struggling with overseed transition at this time. If multiple stress factors occur within a given area, severe turf thinning will occur. These factors include: 

• Shade – Perennial ryegrass has a higher tolerance of shade than bermudagrass and grows more aggressively in shaded areas during the winter months. This inherent physiological difference gives ryegrass the ability to outcompete bermudagrass in shaded areas and large bare areas can result around trees and on north-facing slopes. 
• Traffic– Carts, mowers and even foot traffic are especially stressful to turf during spring transition and can cause turf thinning. Bermudagrass does not grow when temperatures drop below 60°F and continual traffic during the peak play season in Florida removes its leaves. Meanwhile, ryegrass is actively growing during the winter play season and thus gains a competitive edge over the thinning bermudagrass. 
• Nematodes – Plant-parasitic nematodes feed on turfgrass regionalUpdateContents. Nematode feeding combined with the additional stress of perennial ryegrass competition can cause significant turf thinning during spring transition. 
• Water Limitations– An additional stress factor that some Florida courses are dealing with this spring is a reduced ability to irrigate. The amount of water that can be used is governed by the five water management districts in Florida and some have become quite stringent on irrigation reductions. In addition to overall reductions in water allocations, several regions must comply with restrictions that only allow watering greens and tees three times per week and fairways once weekly. It is impossible to keep ryegrass alive without supplemental irrigation and this is causing rapid transition in many areas. 

Soil cultivation and fertilization should be applied in thin areas to promote bermudagrass growth and quality. Also, if areas struggle with nematodes, the nematicide Curfew (1,3-D) should be applied to reduce nematode populations. Irrigation reductions are making turf recovery difficult as well because nematicides and most fertilizers must be watered in with irrigation. 

Spraying tees and fairways on a regular basis with pigments and light amounts of fertilizers, or “liquid overseed” as it is often called, is continuing to gain ground in our region ( see previous Florida Region update). Traditional overseeding with cool-season grasses is a stress to the base bermudagrass that causes turf thinning, whereas liquid overseeding improves turf growth, as it provides nutrients on a regular basis. Also, the turf remains actively growing for more of the winter season due to warmer canopy temperatures. Lastly, traditional overseeding must be mowed regularly throughout the winter whereas non-overseeded bermudagrass is mowed less often. For more information on liquid overseeding please don’t hesitate to contact either of the Florida offices. 

There is only one week left to take advantage of the $600 discount for pre-payment of TAS visits. Payment must be received by May 15 but the visit can be scheduled at any time during the year. Please contact our office to take advantage of this reduced fee.