Rust is one of the easiest lawn diseases to identify. The beginning phase of the infection causes light-yellow flecks on the grass blades and sheaths. The flecks then enlarge and elongate over time, turning deeper yellow in color. These flecked areas eventually rupture, releasing spores that are yellowish-orange to reddish-brown in color, hence the name Rust. A severe Rust infection can cause your entire lawn shoot (all of the above-ground parts of a grass plant) to slow growth and turn yellowish- to reddish-brown. Grass may appear thin as individual shoots start to die off. Toward the end of the Rust infection cycle, leaves can become shredded and point downward if the lawn disease is severe enough. Also, plants infected by Rust are more susceptible to infection from other types of lawn fungi.
A Rust infection can occur only if all of the following conditions are present: 1. Pathogen: Puccinia spp. lawn fungi 2. Host: Bermudagrass, Bluegrasses, Fescues, Ryegrasses or Zoysiagrass 3. Environment: Moist climates with temperatures ranging from 65°–86°F and low-nitrogen soils
Because you can't change your environment, the best way to control Rust is to create conditions that will foster a healthy lawn. Not only will this make your yard unfavorable for Rust growth, but it will also lower your risk of extensive damage should the lawn disease develop—plus you'll have the type of lawn you'll want to live on. For Rust control and lawn fungus treatment, TruGreen® recommends the following cultural control tips: • Use fertilizers with adequate levels of nitrogen • Reduce thatch with core aeration • Reduce shade and improve air circulation • Avoid watering at night • Water deeply one to three times a week, rather than lightly every day, to increase growth