Kill The Bugs – Not The Grass September 30, 2014 By Darin S. Bevard

Insect repellant and sunscreen can severely injure grass. A table was placed on this tee and sunscreen and insect repellant were provided for the golfers. With multiple applications, the damage was significant except in the rectangular area where the table protected the grass. In this case, the damage was so severe that areas of this tee had to be plugged for recovery.

As the growing season winds down, we are frequently asked, “What was the biggest problem with turfgrass over the past season?” Annual bluegrass weevil could certainly be a stock answer. Weevils caused significant damage and required great vigilance and expense to control. Crabgrass and goosegrass were also problematic on many golf courses, and their populations on greens were higher compared to past years. Rather than revisit these problems, this update will focus on a pest problem of a different type, gnats.

Gnats, you say? Gnats are not insects that feed on grass. However, in 2014, they were a major nuisance throughout the mid-Atlantic region. The presence of gnats caused indirect damage to fine-turf areas when golfers sprayed insect repellant to keep them away. The aerosol carriers used in most insect repellants will severely injure grass. When weather conditions are favorable for the turf, the damage is usually temporary but certainly unattractive. Under hot, stressful conditions, insect repellants can kill the grass requiring plugging or reseeding for recovery. Sprayable sunscreen can also cause similar problems.

Application of aerosol products on tees, fairways and greens will cause damage, and this damage was commonplace in our travels this year. Golfers can help by applying aerosol products while standing on a cart path or, at the very least, in the deep rough where damage is less noticeable and will not likely cause more than temporary turf injury. The grass will be better for it.

Source: Darin Bevard (

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