How To Identify And Treat Necrotic Ring Spot

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Necrotic Ring Spot (NRS), attributed to several soilborne fungi belonging to the Ophiosphaerella genus, is a prevalent and vexing ailment afflicting lawns and other grassy expanses. Manifesting as circular patches of deceased and ailing grass, often taking the form of rings or arcs, this condition significantly impacts the aesthetics and vitality of turf areas. This comprehensive guide provides you with the requisite knowledge and strategies to identify, address, and preempt necrotic ring spot, thereby safeguarding your green spaces from the perils posed by this fungal pest.

Identifying Necrotic Ring Spot

  • Symptoms: The telltale signs of NRS encompass circular patches of expired or declining grass, typically commencing as diminutive areas spanning a few inches and progressively expanding to form rings or arcs extending several feet to several meters in diameter.
  • Growth Pattern: Central to the affected region, the grass may exhibit a straw-colored hue or a sunken aspect, while the periphery often showcases a band of luxuriant, verdant growth. Dark fungal structures such as hyphae and pseudosclerotia may be discernible on compatible plant parts in certain instances.
  • Timing: NRS may manifest throughout the growth season, yet its activity peaks in warm, humid climates with moist soil conditions.


Regrettably, no singular, foolproof remedy exists for NRS. Nevertheless, multiple methods can aid in managing the disease and shielding healthy turf areas.

Cultural Practices

  • Enhanced Drainage: Facilitate aeration within the affected area and its environs to augment air circulation and drainage, thereby rendering the milieu less conducive to fungal proliferation.
  • Water Management: Exercise prudence in watering practices to avert overhydration, as excessive moisture serves as a catalyst for fungal propagation. Adopt a regimen of deep, infrequent watering to foster robust root development.
  • Mowing: Adhere to proper mowing heights and abstain from scalping the lawn, as such practices induce stress in the turf, rendering it more susceptible to disease.
  • Fertilization: Sustain soil fertility equilibrium through judicious fertilization practices. Refrain from excessive nitrogen application, as it can exacerbate fungal growth.
  • Fungicides: While fungicides may not eradicate NRS entirely, they can curtail fungal activity and facilitate turf recuperation. Select fungicides explicitly labeled for NRS and administer them in accordance with manufacturer guidelines. Prior to fungicide utilization, seek counsel from a professional lawn care specialist.
  • Biological Control: Preliminary research suggests the utility of beneficial fungi or bacteria as biological agents for controlling NRS. However, this avenue necessitates further exploration before widespread adoption.


Culturing a robust lawn through meticulous watering, mowing, and fertilization practices fortifies turf resilience against disease susceptibility. Additional preventive measures include:

  • Containment Of Fungal Spread: Refrain from transferring soil or equipment from afflicted regions to healthy ones. Thoroughly sanitize tools and equipment utilized in affected areas.
  • Stress Mitigation: Mitigate stressors on your lawn by limiting foot traffic, soil compaction, and protracted drought or overhydration.
  • Variety: Consideration of turfgrass varieties exhibiting resistance to NRS proves prudent. Seek guidance from local nurseries or extension services to identify suitable options tailored to your region.

Professional Assistance

Engaging the services of a lawn care professional like those at Holmes Lawn & Pest can prove advantageous under the following circumstances:

  • Difficulty in diagnosing the problem.
  • Extensive or persistent manifestation of the ailment.
  • Requisite guidance in selecting the appropriate treatment modality.

Necrotic Ring Spot poses a formidable challenge; however, comprehension of its identification, treatment modalities, and preventive measures makes effective management attainable, thereby preserving a flourishing, verdant lawn. Timely intervention, conscientious practices, and recourse to professional expertise, when warranted, serve as linchpins in thwarting NRS and nurturing the vitality of your green space.

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