Publication Date: 07/01/2009

Rust is a disease of bluegrass. It often appears on residential lawns and high-use athletic fields. Rust is largely cosmetic, but the orange spores that dislodge easily from leaf surfaces can be a greater nuisance, covering shoes, pets, and lawnmowers with a rusty residue. These spores, carried by the wind or equipment, spread the disease to other areas during the growing season.

Rust outbreaks are most common in late summer and early fall, although the sometimes the disease is active in the early spring. Summer heat and drought stress along with overuse and compaction contribute highly to the presence of rust on turf.

This turfgrass disease is not harmful to humans, pets or even the turf. In a heavy year, it can make the grass appear thinner than normal but that can be said for just about all grass blades at this time of year. Regular mowing reduces the abundance of orange spores and adding fertilizer can also help. Both of these practices are done by the park district.