When the National Association of Landscape Professionals released their 2018 list of the top 10 U.S. cities at risk for weeds and lawn diseases this past season, one of the largest cities in Ohio was near the front of the pack. Cleveland came out as number three on the list due to its irregular shifts in temperature, poor drainage and generally higher number of rainy days—the combination of which contribute to the spread of lawn fungus.
While the study shows particular concern for lawn disease in Cleveland, the reality is that lawn fungus can take shape in lawns across Ohio under the right conditions (when lawns are stressed or weakened). And when it does, lawn fungus is bound to attack the health of grass, leaving it discolored or patchy and more vulnerable to the impact of environmental conditions.
To provide you with further insight, here’s a list of the most common types of lawn fungus found in Ohio and treatment plans to address existing populations.
5 Types of Lawn Fungus
1. Brown Patch
Caused by a fungus known as Rhizoctonia, brown patch typically begins to pop up in lawns when weather conditions become hot and humid. As its name suggests, this lawn fungus is characterized by circular brown patches with dark outer rings, and is often the result of applying too much fertilizer or allowing water to sit too long on grass.
When a brown patch outbreak occurs, you can use a rake to fluff grass in problem areas. Doing so will help accelerate the drying process for your lawn and return the lawn fungus to a dormant state. You’ll also want to sharpen your mower blades so wounds from dull blades don’t cause the disease to spread further.
2. Dollar Spot
While dollar spot can start as a small yellow spot or straw-colored band on individual grass blades, it can eventually turn grass blades entirely white and spread throughout your yard. The fungus that causes dollar spot, Sclerotinia homoeocarpa, remains dormant in the wintertime and prompts the disease to flourish between late spring and late fall, especially after a wave of very moist weather.
Although grass suffering from dollar spot may look dried out, remember that overwatering can only make the condition worse. That’s why it’s best to water deeply and infrequently, while sticking to a morning schedule (before 10 a.m.) to avoid prolonged wetness overnight that can intensify the impact of the lawn fungus. If areas are severely affected or problems persist, we recommend applying a fungicide treatment to end disease symptoms.
3. Gray Snow Mold
When snow melts in the springtime, not every homeowner is met with the thick, green lawn they had envisioned. Oftentimes, the stress of heavy blankets of snow (combined with the moisture of the season) produce grayish-white patches where grass is matted together—what’s known as gray snow mold.
If symptoms of gray snow mold appear, first rake infected areas to help break up the matted leaves and dry out these sections of grass. Then, you can overseed to treat bare spots and restore the look of your lawn. Make sure you wait for the seeds to settle and actively grow before you mow or fertilize.
4. Pythium Blight
Pythium blight—also referred to as cottony blight—is a lawn fungus that commonly occurs when homeowners use too much water or fertilizer. Most prevalent in hot, humid conditions, pythium blight can sometimes be undetectable at first as it looks like grass wet with dew. However, the greasy feel of the grass blades when wet, combined with its yellow hue when dry, help pinpoint the presence of this fungus problem.
Because sources of the Pythium fungus can remain active in plant debris, it’s best to remove thatch when a pythium outbreak occurs. This can help stop spread of the disease to healthy areas of the lawn. The same can be said for cleaning off mower blades and other lawn tools between uses.
5. Red Thread
While red thread is among one of the first lawn diseases to emerge in the growing season, it can also appear in the fall and winter, too. This type of lawn fungus thrives in wet weather and overcast conditions and appears how it sounds, with reddish threads wrapped around or extending from the tips of grass blades.
Since red thread is prevalent in lawns with low nitrogen levels, one of the most effective routes to recovery is applying fertilizer with the right degree of nitrogen—a factor that a soil test can help define. If your lawn is unresponsive to these efforts or when cases are more extreme, applying a lawn fungicide to kill the active fungus and prevent reinfection is recommended.
Looking for a more proactive approach to lawn fungus prevention? The team at Weed Pro can help create a customized lawn care treatment plan that keeps your yard healthy and green year round. Contact your local provider today for details.