How to deal with red thread disease on your lawn
Q Toward the middle of last summer, our back lawn slowly became infected with what I believe may be red thread disease. At the end of the summer, it was also appearing in our front lawn. I don't believe I saw actual threadlike growth, but patches of lawn slowly became a reddish-golden colour. As we have our lawn professionally mowed, I asked the company if they had other customers with the same problem and was told they did not. We also have our lawn fertilized professionally. None of our neighbours had the same problem.
As spring approaches, I'm concerned about the state of our lawn again this year. I was hoping you might write about this in one of your articles as to what we can do to improve the state of our lawn. One thing I generally do is water late into the evening and I wonder if this could have had an adverse effect on our lawn.
A Since you described the problem as patches rather than spots, I'm assuming it is red thread disease and not dollar spot, which manifests itself with many small spots all over the lawn. Red thread has been a problem in certain areas of Edmonton and Sherwood Park.
You can control the red thread culturally.
The lawn needs to be fertilized regularly as a lack of nitrogen may be a contributing factor to the problem. Since you already suspect you have a red thread problem, I'd fertilize in the spring with a product high in nitrogen such as 27-14-0. Aerate the lawn and have a professional check it for thatch. If there is a thatch issue, have it removed.
Never water late into the evening. Doing so creates the ideal environment for fungi and other diseases. The lawn remains wet and does not have a chance to dry off as it would if watered early in the day.
I have always been a big proponent of watering in the early morning hours. This method gives the lawn moisture to make it through the day and the lawn can dry off properly. Avoid watering in the midday sun as is could create a magnifying effect and scorch plants.
To read more about the problem, I've included a useful information document from the Government of Canada with this column online at edmontonjournal.com.
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