Red Thread: What is it & How Can it Be Prevented

Red Thread: What is it & How Can it Be Prevented

Red Thread is a common lawn disease for Cincinnati residents. How do you know if your lawn has been impacted by this fungus?   When you’re looking at your grass from a distance, Red Thread appears as pink to red patches from 3 inches to 2 feet in diameter. Upon closer inspection of the grass plant, you can see reddish fungal-like structures on the grass plant. Small pink tufts may also be seen on these fugal structures when dew is present.

Why does my lawn have the disease, but my neighbor’s lawn doesn’t?

As with any lawn disease, three factors make up the turf disease triangle. The first is the pathogen itself, which usually resides in the thatch layer. The second factor is a susceptible host. In this case, the host is a cool-weather grass that is low on Nitrogen. The final factor is the environment, or more specifically, the weather conditions. Since it is challenging to remove a fungus from a lawn altogether, and it is impossible to control the weather, the best long-term solution is to disrupt the disease triangle by focusing on the host plant, strengthening it with fertilizer.

Red Thread usually affects cool-season grasses, including Red Fescue, Ryegrass, Kentucky Bluegrass, and Bent Grass. Once the fungus is present in a lawn, the right weather conditions will trigger growth. Remember, the first thing required by the fungus is a suitable host. Once a cool-season grass is low on Nitrogen and isn’t growing rapidly as of late is infected, all that is needed is for temperatures to stay in the 68º to 75º range with high humidity (typical Cincinnati spring), and the disease begins to grow.

Does Red Thread kill the grass?

Red Thread does not kill the grass, although it can appear to be dead. Red Thread is spread by dead affected plant material and by mowing and other mechanical maintenance. The disease may eventually turn the infected grass brown, but the red or pink growths do not infect the crown or the grass plant’s roots. Therefore, the grass plant will not die.

Should I use a fungicide to get rid of the Red Thread?

Fungicides tend to mask the symptoms of a disease, and very rarely do they solve the problem. A fungicide will usually hide the symptoms for 21 to 28 days making the lawn appear healthy again. However, after the treatment period, things can revert to how they looked pre-fungicide. During that 21 to 28 day period, what actually happens is that our weather patterns have likely changed, and conditions are no longer optimal for the disease to flourish. It appears that fungicide killed the disease until the following spring when the disease returns to repeat the cycle.

How can I get rid of Red Thread?

As previously discussed, the only way to beat the disease is to disrupt the disease triangle. We cannot control the weather or remove the disease fungus from the lawn, so we must focus on the host, the grass plant.  

Quality nitrogen-rich fertilization will alleviate the symptoms quickly, restoring the lawn to its natural beauty for the short term. The best long-term plan to beat Red Thread is to aerate and seed frequently, using a grass plant that is not as susceptible to the disease. We recommend Tall Fescue as the ideal grass plant in our area. It is much less susceptible to diseases, it can withstand our extreme temperature changes throughout the year, and produces very little thatch.

If you’re looking for expert lawn care and fertilization in Cincinnati, American Landscapes LLC can help! Click here for a quote or call us at 513-947-8727 to get started today.

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