How to Identify and Control Rust

When lawn disease strikes, your dreams of a thick, beautiful lawn may seem to slip out of reach. But the solution to your problems can be as simple as disease I.D. and changes in your lawn care routine. Most common lawn diseases start with fungal pathogens that can't flourish unless conditions favor their growth. With proper lawn disease identification and disease-fighting culture, you can control disease and enjoy a healthy lawn.

Several different fungal pathogens cause rust diseases in lawns. Rust strikes grass leaves and stems in mild to moderate temperatures, beginning in spring, but it's often most prevalent in fall. Kentucky bluegrass, perennial ryegrass, tall fescue and Zoysia grass are common hosts for rust diseases.1,2

  • Symptoms and signs: Rust first appears as yellowish leaf specks that develop red-orange fungal spores. Lawn areas grow thin and weak, forming large, irregular patches with a rusty tinge.Seasonal lawn care tasks leave shoes, lawn tools and mowers dusted with rusty orange-red spores.
  • Contributing factors: Excessive moisture from high humidity, too much shade, poor air circulation and extended wetness all contribute to rust's germination and spread. Drought stress and underfertilization also support these diseases.
  • Cultural control: Help prevent rust diseases by feeding your lawn adequate nitrogen. Water so grass gets adequate moisture, but never stays overly wet. Improve air circulation by mowing at recommended grass heights and removing grass clippings. Time irrigation for early morning, so grass dries in sun.

When cultural controls fail to manage fungal lawn diseases, a lawn fungicide can help. As with garden fungicides, early treatment is key to preventing fungal pathogens from germinating and spreading. Many effective fungicides are available only to lawn professionals. Your local county extension agent is an excellent source for information on lawn fungicides and their use for lawn diseases.

For any type of lawn disease, choosing disease-resistant grass varieties plays an important role in disease prevention and control. Superior grass varieties such as purebred Pennington Smart Seed grasses are backed by decades of industry-leading research and breeding to provide you with the finest in sustainability-enhancing lawn grasses with outstanding disease resistance.

By being proactive and providing your lawn with the care it needs, you can restore balance and enjoy a thick, healthy lawn again. Pennington is here to help with timely, expert lawn advice and premium seed and lawn care products, so you can know the satisfaction of a disease-free lawn you're proud to call your own.

Pennington with design and Smart Seed are trademarks of Pennington Seed, Inc.


  1. NextGen Turf Research, "Disease Overview: Turfgrass Disease," April 2016.
  2. Bruneau and Lucas, "Diseases of Warm-Season Grasses," North Carolina State Extension, August 1995.

Photo credit: Clarissa Balbalian, Mississippi State University, (CC BY 3.0 US)