Summer patch

Updated 5/6/17

Summer patch is caused by the fungus Magnaporthe poae. Both poa and bentgrass greens can be attacked by this fungus. The fungus attacks the roots of the plants when soil temperatures exceed 65 F but symptoms are frequently not observed until later in the year after roots have been severely damaged. Because the fungus can not be seen attacking the roots, preventive application is frequently needed in the spring at locations where this disease has caused damage in…