Slime Mould

Causal Agent: Mucilago spp., Didymium spp. & Physarum spp.

Susceptible Turfgrasses: All turfgrass species.


  • Fruiting bodies may smother grass blades turning them grey, pink, purple, white or yellow.

  • Affected turf forms rings up to 60cm in diameter as the Slime Mould grows outwards.

  • No immediate damage to turfgrass is evident as slime moulds are not plant parasitic.

  • Fruiting bodies may become so thick on leaf blades that they may reduce the photosynthetic ability of individual leaves.

  • The rings normally disappear within 2 weeks.

Conditions Favouring Disease

  • Excessive thatch favours slime mould development.

  • High levels of soil organic matter are a food source for Slime Mould so contribute to a favourable environment.

  • Cool, wet, humid weather is ideal for fruiting body development.

  • High cut, unmaintained turfgrass with infrequent mowing.

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