Type I fairy rings in warm-season grasses

Type I fairy ring symptoms on a bermudagrass fairway

This spring we've seen a tremendous amount of Type I fairy ring on bermudagrass fairways and landscapes established with zoysiagrass and centipedegrass.  Type I fairy ring symptoms are the most severe, causing decline or death of the affected turf. In most cases these symptoms appeared as soon as the turf began to green-up in the spring. The affected turf never greened-up, indicating that it had been killed over the winter.

Note how the symptoms stop near the drainage basin

How and why did this happen? I suspect that these rings began to develop last year during periods of wet weather in the spring. In fact, some people noted that these same areas had green (Type II) fairy ring symptoms last year. All of this fungal growth may have turned the soil hydrophobic, or water-repellent, and caused the turf to be killed by winter desiccation. Or maybe the extra nitrogen released into the soil profile by the fairy ring fungi caused the turf to be more prone to winter injury.

Either way, the important thing now is to take steps to encourage a rapid recovery. Wetting agents or soil surfactants should be used to re-wet the soil in affected areas, and spiking or aerification should be done to break up the mat of dead turf. Avoid application of DNA herbicides, like prodiamine, as these inhibit root growth and will slow recovery. Fungicides probably won't help to speed up the recovery, but they may help to prevent the problem from recurring next year. For a list of fungicides labeled for fairy ring control, please visit the Disease Management Utility on TurfFiles.

For more information on fairy ring, check out our fairy ring disease profile.