A few weeks back, we wrote a blog on common causes of grass death. We touched a bit on various kinds of fungi and diseases that can kill growth, but our crew has been noticing more and more of these diseases popping up on job sites. We wanted to do a more in-depth look at grass disease, focusing on a few that have been particularly common as of late.
Red Thread usually starts popping up in late summer or early fall. Red Thread won’t kill your turf completely, but it will cover it up with homely thread-like growths. These growths are caused by a fungus, Laetisaria fuciformis, which attacks the tips of grass blades. Red Thread is most common on Kentucky blue grass, ryegrass, and tall fescue, and can be caused by poor turfgrass nutrition. Once it shows up in your yard, it can quickly take over. That’s why it’s important to treat infected turf ASAP.
As mentioned earlier, Red Thread attacks grasses that suffer from malnutrition. The best non-chemical treatment for Red Thread involves adding nitrogen to your turf regular through fertilizer treatments. It could take a few applications over a couple years to completely remove outbreaks, but good grass nutrition will strengthen your yard and prevent Red Thread from coming back and spreading. If you suspect that your lawn is at risk, consider fertilizing sooner rather than later.
Alternatively, you can apply a fungicide recommended for Red Thread in order to quickly kill the disease. One application in addition to nitrogen treatment should be enough to keep the fungus at bay.
Brown Patch is another kind of fungal grass disease caused by Rhizoctonia solani. This disease thrives when it’s hot and humid outside, making it a common summer occurrence. Brown Patch causes grass to thin and turn light-brown in patches (circular spots) around your yard. Patches can become as big as several feet in diameter, and this fungus is fully capable of killing your grass, especially if the turf is young.
Brown Patch is often caused by grass becoming too damp after watering or irrigation. Keep track of your irrigation system and don’t over-water. You may consider installing a rain sensor so that your system knows when storms have moved in. You should also be careful to regularly cut your grass and remove damp lawn clippings from your yard. Aerating your lawn can also help prevent against fungal infection.
Remember: Though nitrogen is good for your yard, too much nitrogen can have an adverse effect. Frequent applications of fast-release nitrogen can encourage the growth of fungi like Brown Patch.
Dollar spot is a very versatile lawn disease that can attack and kill many different types of grass. This fungus takes the form of small, silver-dollar shapes brown spots that may occur dozens of times in a single lawn. Individually, these spots don’t look menacing, but don’t be fooled: Dollar Spot kills turf clear to the roots.
Like Brown Patch, Dollar Spot thrives in hot, humid weather and is often caused by poor watering, mowing, or fertilizing techniques on turf. Be sure to feed your lawn some nitrogen-rich fertilizer, water regularly (especially when it’s humid), and mow consistently. However, don’t mow your lawn too short in the summer (less than 1.5”) or it could become even more vulnerable to disease.
The best treatment method for Dollar Spot is regular, deep watering in the mornings. It is best to let your grass dry completely before evening, since Dollar Spot can spread on wet, cool grass. Keeping up with a good watering routine, checking your soil, and mowing properly are sure to keep your grass hardy and resilient throughout disease season.