Prevention Begins at 55, USGA Northeast Region Update

Posted on April 20th, 2021
By: John Daniels, agronomist, Northeast Region

Monitor soil temperatures at a 2-inch depth to determine when preventative disease applications should be made. 

Whether you’re trying to prevent crabgrass or troublesome soil-borne diseases, 55 degrees Fahrenheit is an important number to remember. That is the soil temperature at which preventative treatments should occur for many turf diseases including fairy ring, take-all patch and Pythium root dysfunction.

Applying a fungicide too early, or too late for that matter, can result in poor protection and leave your greens susceptible to damage this summer. Proper timing is just as important as selecting an appropriate fungicide for a given disease. Even the most effective products can be rendered ineffective if not delivered at the correct dose and time.

Don’t let soil-borne diseases sneak up on you, particularly for sites that have a history of disease damage. Monitor soil temperatures at a 2-inch depth and make applications only when conditions are within the proper window. Some diseases are best controlled at 55 degrees whereas others, like summer patch, are best controlled at 65 degrees. This could be a difference of several weeks. Understand the recommended control temperatures for each disease you are trying to manage and only treat when those environmental conditions are met.

It is important to remember that a well-timed preventative fungicide treatment can not only reduce the likelihood of damage but could also result in less product being used compared to a wait-and-see approach. As the saying goes, an ounce of prevention is worth a pound of cure.

Northeast Region Agronomists:

Adam Moeller, director, Green Section Education –

Darin Bevard, director, Championship Agronomy –

Elliott Dowling, agronomist –

John Daniels, agronomist –

Information on the USGA’s Course Consulting Service

Contact the Green Section Staff

Member of GCSAA