What Causes A Lawn Disease To Develop?

Hand on Green Grass

In order for a lawn disease to develop, three conditions – known as the Disease Triangle – must exist.

1. You need to have the pathogen or disease-causing agent present. Disease spores from the diseases that are common to the area can be found in most home lawns. They usually float in on wind currents, wash in during rain events or are transmitted by animals or people.
2. You need the host plant, which is your turf grass (or tree or shrub). Usually the plant needs to be actively growing in order for the disease to infect it.
3. Finally the third side of the triangle is the environment. When we speak about the environment, we are referring to air temperature and moisture, but still other environmental influences came into play. Mowing too short, letting the turf grow too long, too much fertilizer, too little fertilizer, too much water, too little water, too much shade, poor soil conditions, variety or cultivar of the plant, etc.

However the thing that brings it all together is time. The environment has to exist for a long enough time for the pathogen to develop and infect the host plant. If proper cultural practices are being followed, meaning proper mowing, watering, fertilization and thatch control, the likelihood of a disease developing is greatly reduced – but not eliminated. If conditions are perfect for a long enough time for a disease to develop, that is what it will do.

Case in Point: Red Thread Lawn Disease

This is exactly what happened during the warm spell much of the nation experienced in December. Two of our lawn care franchise owners, Scott Bixby of Wilmington, DE and Charlie Marshall of Centreville, VA, sent in pictures of a disease that is normally seen in the late spring or early summer – Red Thread.

Lawn Disease

For those of us in the lawn care industry, seeing something out of the ordinary is a welcome diversion. However it may not be the same case for our customers. Now that the weather has turned more seasonal, the development of Red Thread has stopped, however the spots will remain until it begins to warm up again. There really is nothing that can be done at this time of year. Marvel at the wonders of nature and dream about warmer days to come. At least that is what I am going to do.

Are you seeing other lawn diseases in your yard? Find your local Spring-Green owner to discuss treatment options and our satisfaction-guaranteed lawn care services.