Fungus on a Zoysia Lawn

Different types of fungus problems attack zoysia lawns leading to severe cosmetic damage and decline in health. Zoysiagrass is vulnerable to fungus when poorly maintained. Fungus infection can be avoided with proper care. Prepare for potential infection with management methods that will keep your home lawn healthy and beautiful.

Care

Vigorous grass has a greater chance of avoiding infection, so employ the basic care requirement for your zoysia lawn. Grow zoysiagrass in areas that offer full sunlight for best growth. Zoysiagrass will tolerate partial sun to partial shade, according to the University of Illinois Extension HortAnswers. Zoysia lawns thrive in moist, slightly acid to neutral, well-drained soil with an ideal pH of 6.0 to 7.0.

Identification

Fungus diseases of your zoysia lawn include dollar spot disease and turfgrass rust. Dollar spot is caused by the fungal pathogen of lanzia and moellerodiscus, according to the Colorado State University Extension. This disease's pathogen was previously referred to as Sclerotinia homoeocarpa. Pathogens are spread on contaminated equipment like lawn mowers. The disease occurs most prevalently when warm temperature suddenly drops.

Turfgrass rust of zoysia lawns is caused by the fungal pathogens Puccinia striiformis, Puccinia graminis, Puccinia coronata and Uromyces species, according to the University of California IPM Online. Rust spreads sporadically and inhabits dormant host plants.

Effects

Dollar spot fungus on zoysia lawns results in spots or stripes on grass leaves that begin as a yellow-green hue. Although this symptom may remain unnoticed, leaf blades experience dieback as the disease progresses with a leaf color change to a tan or purple color, according to the Colorado State University Extension. Lesions may also appear on the tips of leaves, as well as the morning appearance of a white growth that resembles webs that diminishes as the day wears on. Turfgrass rust leads to a display of yellow spots on stems that change to raised red/brown rust-hued areas of fungus. The "rust" rubs off easily, kills lawn leaves and greatly diminishes the health of your zoysia lawn, according to the University of California IPM Online.

Natural Control

For natural control, consistent, appropriate mowing is essential. Mow your zoysia lawn to a height of 1/2 to 1-1/2 inches, according to the University of Illinois Extension HortAnswers. Additionally maintain adequate nitrogen levels as fluctuations significantly affect health; the University of Illinois Extension suggests an application of 1 to 3 lbs. of nitrogen per every 1,000 square feet of zoysia lawn on an annual basis.

Chemical Control

For chemical control of dollar spot, use fungicides as a last option for zoysia lawns and only apply them if your grass has already undergone a previous dollar spot infection. Use a chemical with the active ingredient chlorothalonil or iprodione, according to the Colorado State University Extension. For severe turfgrass rust, apply a fungicide with the active ingredient azoxystrobin or chlorothalonil, according to the University of California IPM Online.