Hello,

I identified the grass as Kentucky Blue grass.

The dying of Kentucky Bluegrass in large areas, accompanied by algae growth, could be due to several factors. Here are some potential causes based on educational resources:

Summer Patch Disease: This is caused by the fungus Magnaporthiopsis poae. It typically begins as circular areas of wilting turf, progressing to reddish-brown or light brown sunken patches. The disease can be severe, with patches coalescing to destroy large areas of turf. More information is at this link:

Turfgrass Diseases: Summer patch (Causal fungus: Magnaporthiopsis poae) (psu.edu)

Necrotic Ring Spot: This disease results in circular or doughnut-shaped patches of dead grass. It often appears two to three years after lawn establishment and is particularly damaging because the fungus attacks and kills the roots and crowns, leading to slow recovery. More information is at this link:

Necrotic Ring Spot of Kentucky Bluegrass - 2.900 - Extension (colostate.edu)

Environmental Stress: Conditions such as high temperatures, limited rainfall, or low soil fertility can cause a decline in Kentucky Bluegrass, allowing weed species to invade and overtake the grass. More information is at this link:

Kentucky Bluegrass (psu.edu)

Poor Soil Conditions:Compacted soil, poor drainage, or an imbalance in soil pH can also stress the grass and make it more susceptible to diseases and pests.

Inadequate Lawn Care: Improper mowing, watering, or fertilization practices can weaken the grass and lead to large dead areas. You might want to get a soil test. Details on soil testing at this link: Get Started | MSU Soil Test

It’s important to correctly diagnose the issue to apply the appropriate treatment. It’s always a good idea to get a confirmed identification as to the problem with your sodded Kentucky Blue grass.

HERE IS WHAT YOU SHOULD DO! - Please send your image by e-mail to the MSU Plant & Pest Diagnostics Lab for a precise diagnosis and identification. The experts there can provide you with the best treatment options. Their email is <personal data hidden> - Please include your name – The lab will let you know if they need a sample sent. FYI – The lab may also ask for additional images too.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details on submitting a sample to MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

Residential Turf

Include a square of turf from the margin of the diseased area so that both healthy and diseased turf is included. Minimally, the turf square should be 6 inches x 6 inches. An intact layer of soil should remain on the root system. Wrap samples in newspaper and pack in a box for shipment. Do not add moisture to the turf prior to shipment. Provide a detailed description of cultural practices (irrigation, fertilization, pesticide application, etc.) and images of the symptoms in the lawn with the sample.

The General Sample Submission Form is at this link:

General_Sample_Submission_Form_May2022.pdf (msu.edu)

I hope this helps! Please let me know if you have any other questions – Thank You