You Are Here: Management Updates 1998 Archive May 19, 1998

Date: May 19, 1998
Category: Diseases
Subject: Red Thread

The recent sunny, windy weather with warmer temperatures should have eliminated Fusarium patch (pink snow mold) activity in most golf courses. It may still appear in wet or shaded areas at higher elevations. Fungal activity in most turfgrass is probably minimal at this time.

Red thread and leaf spot are common in many lawns but do not generally require any kind of treatment. However, stress from mowing off large portions of the leaf blades may increase both of these diseases. In many areas, lawns grew rapidly and the rainy weather kept people from mowing and delaying it until the blades were very long.

In general, red thread will be worse where grass is slow growing due to nutrient deficiency, compaction, and along roads where salt may have accumulated. Leaf spot, which can progress to melting-out, is more severe where excessive nitrogen fertilizer has been applied. Sometimes homeowners will see the lawn thinning out, not recognize the problem, and add more fertilizer to "help it grow" exacerbating the problem. Both diseases are favored by wet weather and will be most severe in areas of the lawn that do not dry out quickly because of poor air movement and shade. Many homeowners will find that overseeding damaged areas is more cost effective than fungicides. The sunny, windy weather may also eliminate the problems better than a fungicide.

Warn homeowners with automated irrigation systems to check the soil to see if water is really needed. Daily watering is rarely needed and is recommended for lawns. Rainfall is probably sufficient at this time of year.

- Submitted by: Dr. Gail Schumann