Leaf Spot and Melting-Out Disease

Leaf spot

What is Leaf Spot?

Leaf spot and melting-out disease are a lawn disease caused by the Bipolaris, Drechslera, and Exserohilum fungal family. These fungi contain organisms that cause turf spots in the spring and fall and rotting in the summer. While leaf spot makes a lawn appear sick, it does not usually cause permanent damage. The melting-out phase of the disease, however, can destroy your entire lawn if it is not treated early. Read on to learn about leaf spot and melting-out disease and how you can keep it from taking over your lawn.

When Does it Occur?

The fungi that cause leaf spot stay dormant through the winter, surviving as spores and fungus strands (mycelium) on your turf. When the moist rain and dew of spring arrive, the fungus starts to grow as its spores are spread throughout the lawn by wind and water.

Summer’s hot, dry temperatures bring about the second part of this lawn disease: the melting-out phase.


Small brown spots begin to show up on grass blades during the leaf spot stage. These spots continue to expand and enlarge on the turf tissue until the disease has taken over the entire blade. This sets the stage for the melting-out phase.

The melting-out phase occurs during summer weather. During this stage, the crowns and roots are severely damaged, which causes the turf to thin out and die. This leaves large, dry, irregularly shaped patches. Because the melting-out phase gives lawns a dried-out appearance, it is often mistaken for drought damage and left untreated until it is too late.


Watering, feeding, and mowing make a world of difference in preventing leaf spot and melting-out disease. Avoid leaving the grass wet for long periods of time or allowing it to dry out too much. Water just once per week in the morning to give the grass the chance to dry and keep fungal spores from spreading. Core aeration and dethatching help keep the turf crowns open and limit the spread of disease. Regular fertilization is another aspect of lawn maintenance necessary in preventing lawn diseases.


Fungicide applications should commence as soon as leaf spot is diagnosed in the spring and summer. Keep in mind that immediate action is your best weapon against the disease because it is virtually impossible to reverse once melting-out has begun.

Take Action

Let us help you in your battle against leaf spot and other lawn diseases. Call us at 614-808-4446 for professional advice and superior results.

Lawn Disease Guide

Download Your FREE Lawn Disease Guide

Even the most manicured landscapes are susceptible to lawn disease. Take some time to learn about identification and removal before one takes over your lawn. This handy guide teaches you how to spot common lawn diseases as well as how to properly treat them.