I Have Hard Fungus in the Lawn

Typhula Blight

• The majority of fungi that would infect your lawn grass are soft to the touch. One exception is Typhula incarnata and T. ishikariensis, two fungal species that cause the disease typhula blight. The disease tends to be more common after snowfall. The hard fungal growths observed in lawn grass are the fruiting bodies of this fungus, called sclerotia. The spherical sclerotia range in size from 3/16 inch to the size of a pinhead, depending on the fungal species in question.

Other Symptoms

• The earliest symptoms of typhula blight can be seen after snow melt; straw-colored patches of varying sizes break out intermittently over the lawn grass. Parts of the patches may have a visible gray mold before the sclerotia break through the soil. Symptoms of typhula blight are sometimes confused with those of fusarium patch, though each disease is caused by a different fungal disease agent.

Control Methods

• Preventative steps can go a long way in protecting your grass from infection by typhula blight. The fungal disease agent of typhula blight tends to develop in large mats of thick grass above the soil surface, so keeping your lawn mowed in the fall can prevent mold development. Avoid heavy doses of fertilizer in late summer or early fall. A fungicide is rarely recommended for typhula blight control unless the yard sees infection every winter on a consistent basis. The hard sclerotia in the lawn can be raked or mowed up if they present a hazard to anyone.

Other Considerations

• The fungi that cause typhula blight are not known to be toxic to humans, but the mushrooms and other fruiting bodies of other fungi are highly toxic to humans. The characteristic of hard fungal growth in the lawn most likely indicates typhula blight infection, but due to the high toxicity of mushrooms to humans, many homeowners prefer to err on the side of caution by not allowing pets or children to frequent the lawn until the fungal infection is controlled.