Lawn and Turf: Rusts
Photo by: R.S. Byther
Biology
Several species of fungi cause rusts of turfgrasses. Typical symptoms include yellow specks on the leaf blades followed by development of yellow, orange, dark orange-brown, or red rust pustules on either or both leaf surfaces. Infection may also occur on stems and leaf sheaths.
Severe rust infections can kill leaf blades and may cause the turfgrass to appear thin or weak. Weedy species can infest weakened turfgrass. Affected areas of the lawn may show a reddish, brown, or yellow tint.
Rust diseases are more severe on slow-growing or stressed grasses (shade, drought, poor nutrition, and incorrect mowing height are possible causes of stress). The fungi overwinters in diseased grass and can be spread by wind.
Rusts typically occur on bluegrasses, ryegrasses, and fine fescues.
Attracting and Keeping Natural Enemies
and Pollinators in Your Yard and Garden
- Native plants provide essential resources.
- Native flora also provides natural overwintering sites.
- Natural dispersion from nearby habitats ensures visitation.
- Some kinds of beneficial insects predatory mites are commercially available.
- Avoid regular use of synthetic, broad-spectrum pesticides.
- Infrequent use of certain narrow-spectrum pesticides is more compatible with some beneficials.
- Extensive lawns are also not conducive to attracting beneficial insects.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Plant mixtures of improved bluegrass varieties.
- Provide proper culture (including adequate, balanced fertilization) to maintain vigorous, healthy turfgrass.
- Water in the mornings so grass can dry quickly. Deep, infrequent watering is best.
- Correct conditions which stress grass. For example, prune trees and shrubs to increase light penetration.
- Mow regularly at recommended height. Remove clippings when rust infections are severe.
- For more information on proper care of lawns, including mowing heights and fertilizer recommendations, see Home Lawns | WSU Extension Publications.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Treat in early spring and fall when grass is growing slowly and the climate favors rust development.
- Do not repeatedly apply the same fungicide or fungicides with the same active ingredient as tolerant strains may result.
- Carefully check product labels.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.