Lawn Fungi: Signs of Fungal Infection in Grass

Jamie Tedder

Weeds are a serious threat to your lawn, competing against your desired grass for water, sunlight, and nutrients. But, there are other things sneakier than such unwanted vegetation, and worse is that they don't usually become apparent until it's too late—fungal disease.

As a family-owned farm providing premium-quality sod grass for sale in Florida, we are committed to helping you create a healthy lawn through sod and grass plugs. This guide will delve into common lawn diseases affecting warm-season varieties like Bermuda and Zoysia grass, what causes them, and how to prevent and eliminate them to keep your lawn thick, green, and disease-resistant.

What is Lawn Fungus?

Lawn fungus refers to various fungal infections that can affect your lawn's health and appearance. It can manifest as discolored patches, irregular growth patterns, or powdery mildew growth on the grass blades, to name a few.

Because lawns are living matter consisting of millions of microorganisms, fungal spores naturally exist in them and usually sit dormant. However, specific environmental conditions can trigger these spores, which then start to multiply, resulting in fungal infections.


What Causes Lawn Fungus?

While lawn fungi are almost always present in the soil, they require the right conditions to become active and develop symptoms.

Excessive heat, high humidity, and poor air circulation are the trifecta that create an optimal environment for fungal diseases to thrive. They often occur when the grass is stressed and weakened due to harsh weather conditions like drought or prolonged periods of rain.

Fungal growth also becomes a concern due to prolonged periods of excessive moisture, often resulting from poor drainage, compacted soil, improper watering, and persistent shade that keeps moist areas from drying. Inadequate nourishment further weakens the grass, making it more susceptible to fungal diseases. Once your grass is infected, the fungi will not dissipate naturally and can spread through various means, including wind, grass clippings, and foot traffic. This underscores the importance of avoiding movement across an infected lawn.

Prompt and appropriate fungus control measures are necessary to treat lawn fungus, prevent further damage, avert future occurrences, and preserve the hard work invested in your lawn.

Signs of Fungal Disease on Infected Grass

Because the symptoms of fungal disease are similar to those of drought, it's essential to accurately identify the issues affecting your lawn. Lawn fungus can come in different forms, but some of the common signs of lawn disease to look out for include:

  • Large, irregular patches of dry grass that seem dead
  • Brown or dead-looking spots on grass blades
  • Thin, red, thread-like strands extending from grass blades
  • Light green or yellow patches of discoloration that grow in size
  • Circular, tan-colored spots on the grass
  • A threadlike or powdery substance on grass blades


5 Common Fungi in Lawns

The mix of wet and humid conditions is a prime factor that triggers fungal growth. Unfortunately, the warm and humid weather prevalent in Florida not only creates a favorable environment for warm-season grasses like Bermuda and Zoysia grass to thrive but also for common fungal diseases like brown patches, leaf spots, and fairy rings to develop.

Brown Patch

Brown patch is usually triggered by prolonged exposure to moisture and high humidity, commonly affecting warm-season varieties like Bermuda grass. It starts as a small, yellow patch that develops into brown or reddish-brown circular areas with darker edges and wilted leaves.

Dollar Spot

This lawn disease earns its name from its initial appearance—a small circular spot, often the size of a silver dollar. It manifests as lesions on the grass blades, displaying brown to white coloration, and can potentially kill the grass down to the roots.

Gray Leaf Spot

Gray leaf spots resemble the initial stages of brown patch disease. Primarily affecting the top of the leaves, they manifest as small spots with gray spores in the center, creating a velvety gray appearance. This fungal disease can be attributed to excessive moisture, soil compaction, poor air circulation, and the overuse of nitrogen fertilizer.

Root Rot

Root rot is triggered by various fungi thriving in consistently moist soil conditions. This results in a loss of vigor in the grass, stunted growth, and yellowing, ultimately leading to a decline in grass quality and density. The grass may also wilt and eventually die.

Fairy Ring

Despite its whimsical name, fairy ring disease is a troublesome lawn disease that often exists long before displaying visible damage, making it difficult to manage. It spreads through the root system, creating small rings of dark green grass that eventually turn brown as the grass succumbs to death. Small mushrooms may also appear at the ring edges.


How to Treat Lawn Fungus: Treatment and Prevention

A targeted fungicide treatment is key to addressing the fungal disease affecting your lawn. Choose a fungicide specifically formulated for the identified fungi and apply it according to the product instructions.

For effective fungicide application, we recommend spraying the product when there is little or no wind, preferably during the early morning or late afternoon. Ensure accurate and thorough coverage, focusing on the affected areas. Repeat the treatment if necessary.

Successful fungus control goes hand in hand with practicing proper lawn maintenance, serving as a proactive measure to prevent the growth and recurrence of lawn fungus. Essential practices such as improving drainage, dethatching, adequate watering, fertilizing, and regular mowing collectively create an environment less conducive to fungal growth. Meanwhile, consistent monitoring and prompt action can contribute significantly to maintaining a healthier and more resilient lawn.


Restore Lawn Health Through Sod Installation

Fungal damage is unavoidable, but you can confidently restore your lawn with Bethel Farms sod. Our premium-quality sod offers a fast and efficient solution to revive your lawn, ensuring a lush and vibrant appearance.

Start by preparing the soil for laying new sod: remove dead grass and any debris. Fertilize the soil with nutrients to support the grass as it adapts to its new environment. Afterward, carefully lay the sod in a staggered pattern, ensuring tight seams and avoiding any gaps where weeds may emerge. Water adequately during the initial establishment period to promote root growth.

The benefits of laying new sod are manifold—it prevents soil erosion, instantly transforms your landscape with vibrant greenery, offers effective weed control, and requires less irrigation compared to establishing a lawn from grass seed. Whether you're replacing affected areas or establishing a new lawn, our grass sod solutions emerge as a reliable and effective way to address the aftermath of fungal damage.

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