Zeroing in on Large Patch

Zeroing in on Large Patch

Here in the Southeast, most turf managers consider zoysiagrass a hardy, easily maintained turfgrass for use on home lawns, commercial turf areas and — of course — golf course fairways. Since zoysiagrass is drought tolerant, grows in any type of soil and requires minimal mowing, it’s often an attractive alternative to bermudagrass.

But zoysiagrass does have its downside. It is particularly susceptible to a disease commonly known as Large patch’ — caused by a strain of Rhizoctonia solani. Environmental conditions favoring Large patch development are cool soil temperatures and wet conditions. Visual symptoms can occur in the fall and spring as circular, discolored patches that expand over time.

Mike Kellum

Mike Kellum, FMC Market Specialist – Southeastern Region


Most common symptoms of Large patch include a round pattern of brown grass with a yellowish-colored ring of wilted grass at the perimeter. These lifeless, discolored circles can enlarge and join together, reaching diameters of six feet or more!

All in all, it is not a pretty sight for turf managers. But take heart! There are ways to prevent and control this unsightly fungal pest.

Cultural Practices Can Help

Here are some integrated pest management practices to try:

Fertilization: Use slow-release nitrogen fertilizers on zoysiagrass to maintain adequate, but not lush, growth during the growing season. Avoid late fall or early spring fertilization.

Mowing: Mow only when grass is dry, making sure to remove no more than one-third of the top growth. Power raking can be used to manage thatch buildup.

Pruning: Prune trees and shrubs to allow light infiltration and air movement to reach turfgrass.

Watering: Since frequent watering enables disease development, try to limit watering to once a week.

Drainage: Good surface and subsurface drainage go a long way to reduce the humidity that leads to disease development in the turf canopy.

Fast, Effective Fungicide Protection

In the event that Large patch does infect your zoysiagrass turf, Fame™ fungicides will provide fast, effective control of this disease and most other major turf diseases. A family of FRAC 11 group (Strobilurin) products that deliver fast-acting, patented fluoxastrobin protection, Fame fungicides are rainfast in 15 minutes and can be used on all types of turfgrasses.

Fame products good for Large Patch are:

  • Fame SC: a suspension concentrate fungicide that protects against zoysia patch, brown patch, pythium blight, summer patch, gray leaf spot, and light-to-moderate infestations of dollar spot. It provides rapid foliar and root uptake with xylem and translaminar movement.
  • Fame Granular: a spreadable, competitively priced fluoxastrobin fungicide offers flexible surface application and excellent uptake and movement within the plant, ensuring fast-acting disease protection.
  • Fame +C: a suspension concentrate fungicide that combines the systemic activity of fluoxastrobin and the proven contact action of chlorothalonil to provide a complete turf fungicide premix. Fame +C offers broad-spectrum protection against 30 prevalent diseases, including Large patch, anthracnose and brown patch.

A fall or spring application of Fame fungicide will provide proven protection against tough turf diseases including Large Patch. It’s a good way to enjoy the benefits of zoysiagrass turf — without experiencing the downside.


Photo courtesy of Ken Hutto.