It interferes with proper maintenance practices, the playability of the turfgrass and the overall appearance of the fairways. Affected turf can become thin and the playing surface can soften. Currently, no pesticides are registered for controlling earthworms in the U.S., which severely limits the ability of superintendents to manage this highly destructive problem. Earthworm populations can reach several million under golf-course fairways, with millions more in the roughs, unnoticed due to higher mowing heights. Unfortunately for superintendents, the basic cultural practices that produce excellent fairway surfaces also create optimal living conditions for earthworms.
Earthworms feed on fairway clippings returned after mowing and on organic matter in the soil.
They love the consistent, moist, fertile conditions that typically are present in fairway turf. In other words, earthworm casting is not an indication of a superintendent's inability to grow healthy turf. In fact, the opposite is true. Based on field observations, Lumbricus terrestris, commonly known as the night crawler, is the earthworm species causing severe casting damage on golf courses in many locations across the country. Night crawlers can live long lives, with a reported average life span of six to nine years.