Management strategy to reduce the likelihood of earthworm casts in your turf.
Causal organism: three major species most closely associated with casting:
|Host grass types||All turf types|
|Symptoms||Some species of earthworms leave casts on the turf surface and this can have a negative impact on the performance and quality of the turf (unevenness, deterioration under traffic, weed invasion, mole activity).|
- Earthworms have an important role in helping to aerate soils, reducing compaction, improving water penetration and infiltration rates, processing organic matter, and reducing thatch.
- Earthworms come to the surface under moist soil conditions (e.g., in late fall and winter) and retreat downward in dry weather.
- Earthworm casting is increased: if grass clippings are returned, when organic fertilizers are used, in liming or using alkaline water for irrigation.
Management strategy to reduce the likelihood of attack
- Reduce thatch in a programmed approach to minimize food sources for earthworms.
- Make minimal use of organic amendments.
- Lower the soil surface pH to discourage earthworm activity by using acidifying fertilizers.
- Minimize the amount of clippings returned to the soil (organic material) by use of slow-release fertilizers or plant growth regulators.
- Use sand top dressings to help create casts that scatter and disperse.
- Brush or switch to disperse casts when dry.
Preventive strategy (guidance only)