We saw these conditions near the end of July 2016, where we had 19 days over 90 degrees and some large rainstorms. It requires extreme heat and humidity, which often comes with large amounts of rain that are followed by a drought. Grasses Susceptible: Kentucky Bluegrass is the type of grass that is the most susceptible, but tall rescue and perennial ryegrass can also see Ascochyta Leaf Blight damage occasionally.Ĭonditions Favoring Disease: The conditions that produce this disease are a large reason that the state of Michigan rarely sees Ascochyta Leaf Blight. Although this grass may look dead, the crowns of the grass and the lower stems are rarely killed and you can typically expect an 80 to 100% recovery within a few weeks, according to Iowa State University. This disease will leave large irregular patches or streaks of turf a straw color, as well as collapsed tips of grass. We looked into the situation further and found some information on this disease, which is rare in Michigan because of the weather conditions that it requires. Some of our customers called us and mentioned that it appeared as if we had burned their lawns, but we looked in their history and we had not applied weed control and could not find any excess fertilizer in the affected sections of grass. If your lawn has suffered from ascochyta leaf blight, or if you're looking to identify and repair another lawn disease, contact your local Spring-Green lawn care team.Symptoms:Ascochyta Leaf Blight is a disease that looks similar to a fertilizer burn, which is part of the reason that we found out about the disease. There are times when you have to use some detective skills to determine the cause of brown spots in a lawn. If any of you have a septic system, you are very familiar with the lines of dry grass that form where the drainage tiles are located. In my years of working on suburban lawns, I have found 4 X 8 sheets of plywood, old sidewalks and patio blocks, as well as many other items, that show up as the weather turns dry. My guess is that it is some sort of utility structure buried in that area. It is fairly easy to see that there is something square located just underneath the ground. Although it may look like a lawn disease, it sometimes isn’t. Many times, buried debris or other structures lurk a couple of inches below the surface and can present some unusual shapes in a lawn, such as what you see in this picture. A fungicide will not help as the disease has already done its damage. Since it has been dry, water will help the grass recover at a faster rate. The turf will recover, but it will take a couple of weeks. If you see sections of your lawn that look like the picture above, you will notice that the grass blades have turned tan from the tip down, but are green at the base. The one good thing about this disease is that it is not a crown killer and the plant will recover on its own.

The lawn disease is called Ascochyta Leaf Blight. It mainly affects bluegrass and it is usually on lawns that were mowed too short.Mowing during the heat of the day seems to be one of the factors that cause this disease to become active.

Lawns have been growing well and then heat and humidity blankets the area.It usually occurs during the period of time when the weather switches from cool and wet to hot and humid.For the last several years, a minor disease has been affecting many lawns during the late spring into the early summer:

Ascochyta leaf blight