Red Thread Fungus
Red thread fungus is the most common disease that we encounter. It attacks the upper blades of grass. It first appears as pinkish spots, usually 3-6” in diameter in sunny areas of the lawn. It may then progress to sprout string-like red hyphae, or “threads.” Severe cases may result in the circles coalescing to create one big patch. The good news is that it does not affect the most important parts of the plant, which are the crown and roots. This makes it the least damaging to the lawn, in the long run, but it can become very unsightly. The affected areas will turn brown as the weather warms and the disease goes dormant. It can take a long time for these spots to grow out and disappear.
Fine fescues are most susceptible, followed by perennial ryegrass, then Kentucky bluegrass. Bentgrasses are usually not affected.
Since it attacks the upper grass blades, it becomes noticeable quickly. It usually shows up during periods of prolonged moisture, when temperatures are in the 60’s and 70’s, (typically late May-June) and the first flush of spring growth slows down. Conditions that favor the disease are warm, humid, and rainy. Watering too often will make it worse.
An application of nitrogen can help, but there’s no guarantee that it will clear it completely. As a matter of fact, it can increase the chances of having more serious disease problems besides red thread. We can apply fungus controls, but they are costly and just control it for a period of time.
We can apply fungus controls for more serious cases, though they’re not a complete cure. They simply control it for a period of about 1 month.
What you can do:
Water as we instruct you to. We leave instructions at each service. This disease is greatly influenced by how often the lawn is watered. Reach out to us if you're unsure.
If the disease is severe, pick up grass clippings.
In severe cases, a spray of 10% bleach solution on mower wheels, deck, and blades will help control the spread.
