Pythium Blight Disease Inspection Guide

When inspecting your lawn for Pythium blight, it's important to learn the earliest signs of fungal lawn disease so that you can decide on the right treatment and begin as soon as possible.

The fungal pathogen that causes Pythium blight can survive in plant debris, soil, and water in addition to living in the plants it may have infected. The easy transportation of Pythium spores means that this lawn disease can be found in any type of turfgrass where enough moisture is present.

This disease can attack all types of grasses, but the effects are usually more damaging to cool-season grasses. The damage caused by Pythium blight can be especially hard on ryegrass used in an overseeding situation among bermudagrass.

Pythium blight can strike your lawn any time during the active growing season of the turf, but damage is most likely to happen during hot and humid weather. Daytime temperatures in the 80's or 90's and humidity levels above 90% are perfect conditions for Pythium blight to take hold of your lawn. In conditions like this example, major portions of your lawn could be destroyed by blight in under 48 hours.

Grassy areas that have been recently seeded or overseeded during this type of warm, humid weather are the most vulnerable to Pythium blight.

If you aren't sure if you have Pythium blight or if it may be a different turf disease, you can check by asking your local extension office. There, a volunteer or master gardener will be able to identify your turf disease.

Pythium blight spreads especially well in turf that is growing in dense, alkaline soil. High nitrogen levels in the soil also encourage this lawn disease. You can learn more about the pH level of your soil and how it affects the growth of plants and fungi with our Soil pH guide.

A layer of thatch on a lawn, dense, compacted soil, and standing water due to poor drainage can all encourage Pythium blight to make a home in your lawn, so it pays off to keep your property well maintained and your lawn healthy.