Fairy ring

Rings/arcs of dark green stimulated grass, or rings of dead turf, sometimes with mushrooms or puffballs. Hydrophobic (water-repellent) soil often develops beneath.

Fairy ring symptoms can manifest in a variety of ways depending on the type of fungus that is causing the issue. The most common symptoms include arcs, rings, or circles of dead grass, which can be accompanied by a lush growth of grass in the center of the ring. This is known as the "green ring" symptom. Another symptom is a circular patch of dead grass, referred to as the "dead circle" symptom. In some cases, mushrooms or other fungi may also appear in the affected area, which is known as the "ring of mushrooms" symptom. These symptoms can vary in size and severity and may be more pronounced in areas of the turf that are already stressed.

The signs of fairy ring in turf can include the presence of mushrooms, which can appear as small, round, or irregularly shaped caps, typically emerging from the soil. They may be tan, brown, or gray in color. Another sign of fairy ring is the presence of mycelium, which is the vegetative part of the fungal organism. It can appear as a white, cottony, or cobweb-like growth on the surface of the soil. Additionally, spores may be present, which are reproductive structures that are produced by the fungus and can be seen under a microscope.

The fairy ring fungi is not a true pathogen, meaning that it does not directly kill the plant. Instead, it occurs when organic matter is degraded by one or more organisms, which releases Nitrogen and increases ammonium levels in the soil. This can become toxic to the plant, causing it to die, or the soil can become coated and become hydrophobic, which can also harm the plant.

Fairy ring is a common fungal disease that affects many types of turfgrass, including lawns, golf courses, and sports fields. It is caused by a variety of fungi, including Marasmius oreades, Agaricus campestris, and other Basidiomycetes. The fungus can be found in the soil and can survive for many years. The disease is typically active in the spring and summer when temperatures are warm and moisture levels are high. It is most severe in sandy soils with high levels of organic matter. The disease spreads through the growth of the fungus's mycelium through the soil.