Grass/Lawn Fungus

Asked April 28, 2015, 3:48 PM EDT

We are in Grants Pass. Hopefully you can answer a lawn question. Our lawn has a strange orange fungus or mold that is growing on it. The stuff comes off on your shoes as you walk. The fungus also seems to precede the grass turning yellow and dying in spots. The lawn is under an oak tree and numerous pine trees. Any guess how to eliminate this fungus? We don't over-water and cut the lawn once a week about 3 inches tall. I aerated the soil last year and use light applications of commercial lawn feed per their recommendations. Thanks for any suggestions. Mahlon and Becky

Josephine County Oregon

1 Response

Looks like your turf grass has rust. Rust usually occurs on bluegrass, ryegrass, or fine fescue. Rust disease is most severe on these turf grass types when slow growing or stressed. Shade, drought, and poor nutrition are what make this disease most severe. Your grass is in the shade of trees, and the trees compete for moisture with the turf grass.
To improve your turf grass, fertilize and water to maintain rapid growth. Turf grass in your area generally needs about 1 inch of water a week during April and May, and 2 inches a week during June July and August. Grass generally needs a nitrogen dominant fertilizer like a 28-3-3. Most fertilizers for lawns will say on the bag how many square feet the bag will cover. When mowing remove the grass clippings when the diseased leaves are present. The grass clippings can be composted. Fungicide sprays can be used as a preventative after making adjustments with the recommended cultural practices. Fungicides will not eradicate an existing rust infection, but they will keep new grass from becoming infected. Homeowner available fungicides include Immunox, or Bravo.