rust grass disease

Lawn Rust close up

rust grass disease

Lawn Rust


Cool Season Grass

Grass species affected

  • Bluegrass
  • Ryegrass
  • Tall Fescue

Disease occurrence

  • Summer through early fall
  • Rust develops during times of drought and as a result of poor fertility.


Warm Season Grass

Grass species affected

  • St. Augustinegrass
  • Zoysiagrass
  • Rust may be observed on perennial ryegrass used to overseed lawns during the winter months.

Disease occurrence

  • May through October
  • Rust typically occurs due to nitrogen deficiency.
  • Rust typically develops due to nitrogen deficiency and during times of drought.


  • Small, yellow specks on leaf blades and stems that develop orange or red pustules.
  • Heavily infected lawns may have an orange or reddish hue and may begin to thin out.
  • The “rust” will be visible on mowers and shoes.


  • Maintain a regular fertilization schedule, as rust typically occurs as a result of nitrogen deficiency.
  • Mow unaffected areas first and diseased areas last to avoid infecting a healthy lawn.
  • Collect and dispose of grass clippings in the garbage when rust is present.
  • To avoid spreading the fungus, after mowing, clean the mower blades by rinsing with water and drying with a cloth.
  • Water deeply and infrequently early in the day to allow the leaf blades to dry off and not remain wet for long periods of time.