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.
For more information on using pesticides, visit
Home and Garden Fact Sheets | Pesticide Resources and Education Program | Washington State University.
Also visit Pacific Northwest Pest Management Handbooks.
- 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
Examples of pesticides that are legal for home use in Washington State are listed below.
The list may not include all products registered for this use.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.