closeup of rust spores on zoysia

Zoysia rust pustules
Clarissa Balbalian, Mississippi State University, Bugwood.org

Updated: April 28, 2021

Several species of rust fungi cause diseases of turfgrasses in Maryland. Given the right conditions, rust diseases may infect most of the turfgrasses grown in Maryland.

The first symptoms appear as yellow to orange spots on leaves and stems. These spots enlarge and cause elongated lesions that produce powdery orange to red to brownish spores. These spores rub off easily on hands, shoes, and clothing. 

spots that form on turf blades from rust
Leaf spots from rust
Photo: Dr K. Mathias (retired), UMD

Severely infected areas will have a yellowish or orange appearance and become thin and weak. Rust diseases can occur all season and are favored by temperatures between 70-75 F with high humidity, heavy dew, or rain.

Management

If possible, select rust-resistant cultivars when establishing turf. Maintain proper levels of nitrogen fertilization and avoid evening irrigation.

Additional information

(PDF) Rust Disease | Purdue Extension Turfgrass Disease Profiles