Large Patch, or sometimes called Zoysia Patch, is a troublesome turf disease now in the Tulsa and Oklahoma City areas. It’s caused by a fungus called Rhizoctonia solani, which is found naturally in the soil. As its name implies, Large Patch Disease results in the formation of large patches of blighted turf that sometimes can exceed 20 feet in diameter. This disease mainly occurs in zoysiagrass, but under certain conditions, some varieties of bermudagrass can also get this disease. Wet and rainy weather, with mild temperatures are prime conditions for this, and that’s what we’ve been experiencing. Symptoms appear as large yellow to brown areas, often circular shaped, which can be up to several feet in diameter. A light orange ring is often found around the very outer edge next to the healthy turf, where the spot is spreading out. Spring Dead Spot in bermudagrass is similar, but the spots are smaller.
Large patch of Zoysia is a disease that can wreak havoc on any lawn during relatively cool and wet conditions. The disease is most common in the early spring and late fall as the turf is entering winter dormancy or breaking dormancy. Symptoms of Large Patch appear in roughly circular patches from 2′ up to 10′ or more in diameter. The affected turf will initially be orange, yellow, or reddish-brown in color but will then turn tan and collapse to the ground. The disease can spread rapidly to encompass large areas of turf, and distinct circular patches may not be obvious in these cases.
Hot conditions as we have in summer will dry things out, and the disease goes away. But again in fall, with mild temperatures and high rainfall, it can come back again. Zoysiagrass is so slow to recover from damage that we recommend a spring and a fall fungicide treatment to turf to help prevent this from occurring. If it’s present now, we highly recommend treating turf, as it can quickly spread, damage, and even kill turf.
An annual program with both spring and fall treatments will greatly decrease the incidence of Large Patch in your lawn. For more information and to set up service for treating for Large Patch, call our office at 918-249-5296, or click here.