Earthworms increase soil health. Moderate levels of earthworm activity in golf course soils can actually be beneficial for helping to decompose plant material and accelerate nutrient recycling. It is only the casts on the surface that are detrimental to course maintenance and playability.
A certain amount of patience and understanding by turf managers and golfers is critical. We cannot expect to completely rid golf course surfaces of any signs of earthworm activity and must learn to live with these tiny creatures. Often, the best approach is to simply break up the casts and drag them back into the turf canopy. Those who deal with cast issues for more than a couple of isolated times per year might need to implement some additional measures. As always, make sure to fully read and understand any pesticide and fertilizer labels and apply them in accordance with the directions.
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Edwards, C. A. 2021. The living soil: earthworms. Natural Resources Conservation Site. USDA.
Oleszek, M., and W. Oleszek. 2020. Saponins in food. Springer, Singapore.
Potter, D. A., C.T. Redmond, and D.W. Williams. 2011. Controlling earthworm casts on golf courses. USGA Green Section Record. October 21. 49(41): 1-4.
Riga, E., J.D. Crisp, G.J. McComb, J.E. Weiland, and I.A. Zasada. 2020. Directed energy system technology for the control of soilborne fungal pathogens and plant‐parasitic nematodes. Pest Management Science. 76(6): 2072-2078.