UC Cooperative Extension Ventura County
669 County Square Dr. Suite 100
Ventura CA 93003
Our offices are currently closed due to the COVID-19 pandemic, and our team is telecommuting from home. We are available via phone and email.
Click here for our office directory: Contact/Staff Info
Rust on Lawns
Many cool-season grasses, for example, bluegrass, bentgrass, ryegrass and others are susceptible to attack by a rust fungus. Within these grass groups, there are cultivars with different levels of resistance to attack. Therefore, you will probably note that your lawn is not uniformly infected, as most lawns are a mixture of grass species and cultivars. The rust fungus survives year-to-year in your lawn. It is usually in spring that temperature and moisture conditions are favorable for the rust to grow, reproduce and infect new tissues causing the yellowing.