How to Identify and Control Brown Patch

Turf showing signs of infection with Brown Patch (Rhizoctonia solani).

When lawn disease strikes, your dreams of a thick, beautiful lawn may seem to slip out of reach. But the solution to your problems can be as simple as disease I.D. and changes in your lawn care routine. Most common lawn diseases start with fungal pathogens that can't flourish unless conditions favor their growth. With proper lawn disease identification and disease-fighting culture, you can control disease and enjoy a healthy lawn.

Brown patch disease strikes lawns from late spring through summer months, continuing into fall. All parts of the grass plant — from roots to blade tips — are affected by this disease. Bermudagrass,perennial ryegrass, and tall fescue are common brown patch targets. The disease often attacks fine fescues and Kentucky bluegrass as well.1,2

  • Symptoms and signs: Brown patch may show itself as early as spring green-up, especially in Bermudagrass lawns. Sunken, circular patches of dead, tan grass appear, measuring up to 3 feet in diameter. The patches expand up to 20 feet wide, ringed with smoky, grayish margins of wilted, dark, dying grass.
  • Contributing factors: High humidity combined with hot temperatures during spring and fall favor the development of brown patch disease. Overfertilizing, overwatering, heavy thatch buildup, and mowing too short contribute to the disease.
  • Cultural control: Fight brown patch disease with good water management to avoid overwatering. Water early in the day, so grass dries well by night. Avoid excessive nitrogen fertilizer, and dethatch if your thatch layer is more than 1/2 inch thick. Follow guidelines for proper mowing to avoid mowing too short.

When cultural controls fail to manage fungal lawn diseases, a lawn fungicide can help. As with garden fungicides, early treatment is key to preventing fungal pathogens from germinating and spreading. Many effective fungicides are available only to lawn professionals. Your local county extension agent is an excellent source for information on lawn fungicides and their use for lawn diseases.

For any type of lawn disease, choosing disease-resistant grass varieties plays an important role in disease prevention and control. Superior grass varieties such as purebred Pennington Smart Seedgrasses are backed by decades of industry-leading research and breeding to provide you with the finest in sustainability-enhancing lawn grasses with outstanding disease resistance.

By being proactive and providing your lawn with the care it needs, you can restore balance and enjoy a thick, healthy lawn again. Pennington is here to help with timely, expert lawn advice and premium seed and lawn care products, so you can know the satisfaction of a disease-free lawn you're proud to call your own.

Pennington with design and Smart Seed are trademarks of Pennington Seed, Inc.

Sources:

  1. NextGen Turf Research, "Disease Overview: Turfgrass Disease," April 2016.
  2. Bruneau and Lucas, "Diseases of Warm-Season Grasses," North Carolina State Extension, August 1995.

Photo credit: William M. Brown Jr., Bugwood.org (CC BY 3.0 US)

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