Fairy ring

Symptoms

Arcs or complete rings, from under a metre to many metres across, of dark-green, fast-growing grass, often with a band of dead or thinned turf just inside, and small tan mushrooms appearing after rain. In dry weather the ring zone becomes hydrophobic (water-repellent) so the grass there wilts and browns even when surrounding turf is green; a mushroom smell and white fungal threads are found in the thatch and soil.