Preventing and Controlling Fairy Ring
Preventing and managing fairy rings on putting greens can be vexing. For example, 60+ species of fungi create fairy rings in turfgrass, and these species vary in their sensitivity to fungicides.
Good cultural practices, such as topdressing and core aerating to prevent excessive thatch, are a good jumping-off point. Once fairy rings have popped up, begin a control program. A fairy ring control program should start with a core or needle tine aeration to the affected area. The aeration will allow water and oxygen to move into the root zone.
When it comes to adding fungicides into your control program, several families of fungicides control fairy ring well. DMI fungicides, such as ArmorTech’s TEB 360 XL and Nufarm’s Tourney work great as preventative and curative applications. The Strobilurin family (FMC’s Fame SC, BASF’s Insignia, and Nufarm’s Pinpoint) is also effective. Note: If using a PGR, consider the PGR and DMI fungicide rates to avoid over-regulation of your turf.
Add a penetrant like Hydro-Pak Command to your tank to help move the fungicide into the root zone. Before the spray begins to dry, immediately follow the application with 0.25″ of irrigation.
If there is a history of fairy ring, start a preventative program in the springtime when average soil temperatures at a depth of two inches reach 55 to 60 degrees. You may have to experiment to see which fungicides work best for your particular situation.