Fusarium blight or fusarium patch on lawns is caused by the soil-borne fungus (Fusarium) which during hot weather causes brown patches on lawns and turf. Fusarium blight on lawns normally attacks Kentucky bluegrass and other bluegrass varieties. Fusarium disease normally starts out as small patches, only a few inches in size, which grow during hot weather conditions and can reach several feet in diameter.
Once the extreme symptoms of Fusarrium Blight become visible on a lawn, it is not possible to control the disease during the current growing season. To prevent the reoccurrence of the disease the following season, avoid using high nitrogen fertilizers and the following spring, before the signs of the disease re-emerge, spray the grass with Monterey Fungi Fighter. Repeat the spraying 2 additional times (as needed) every 14 to 21 days.