Fairy Ring Fungus
Fairy ring fungus appears as rings of dark green or dead grass. It is fungus that grows underground long the root system of the grass.
This fungus grows in a circular pattern breaking down the organic matter in the soil. The breaking down of organic matter releases nitrogen causing the infected grass to appear dark green.
Fairy ring fungus fruits mushrooms which appear on the outer edge of the ring. As the fungus invades the grass root system it makes it impervious to irrigation causing the affected area of lawn to die.
This type of fungus are found during warm to hot periods with ample rain. When grass begins to turn brown and die, puncture the ground to improve the irrigation to the roots.
Treatment for Fairy Ring Fungus
Fingicides containing Dichlorophen.