Dollar spot is one of the most widespread and persistent lawn diseases. This fungal disease creates distinctive, circular patches of discolored grass that resemble silver-dollar-sized spots, giving it its name. While it may not immediately kill grass, it weakens turf and can lead to long-term damage if left untreated.
Join the Simple Lawns team as we discuss how to identify and control dollar spot so you can prevent it from taking over your turf!
Dollar spot is a disease that appears as small, silver dollar-sized patches on the lawn. If your lawn falls victim to dollar spot, you will notice individual blades of grass beginning to turn tan or yellow. The affected areas will spread to form small patches (smaller than brown patch) of damaged grass. These damaged patches will appear to be sunken into your lawn, and they are typically about the size of a silver dollar, which is how the disease got its name.
Affected grass blades begin developing straw-colored markings that are typically surrounded by a brownish border. These markings begin at the tips of the leaf blades and slowly work their way down to infect the entire blade of grass. Older lesions form into an hourglass shape on higher-mowed lawns, which is an easy identifier of dollar spot. Look for the identifiers listed below to help differentiate dollar spot from other lawn diseases:
Historically, there has been a bit of debate about the fungus responsible for dollar spot, but most experts believe the Clarireedia genus to be the culprit. Many of the fungi in this genus form at temperatures between 60-75 degrees Fahrenheit, but they can and will form outside of this temperature range if humidity is high.
Clarireedia jacksonii is the fungal species most often identified as dollar spot, but a few other species within the same genus are occasionally responsible. This fungus attacks the leaf blades in your lawn, as dollar spot is a foliar disease. Underfertilizing and excessive moisture commonly cause dollar spot to develop, and mowing too low makes it easy for this disease to spread.
The type of grass in your yard plays a big role in the development of dollar spot. Certain species of the Clarireedia genus attack only cool-season grass types, and others attack all grasses indiscriminately. Fine fescue, perennial ryegrass, and bentgrass are common grass types that can be affected, but warm-season grasses like Bermudagrass or Zoysiagrass are also susceptible. Below is a list of a few common causes of dollar spot:
When conditions are right, the fungus can quickly move from one area of the lawn to another, infecting healthy grass and expanding the size of the affected patches. Lawn maintenance practices can unintentionally accelerate the spread of dollar spot. Mowing over infected grass without cleaning mower blades, leaving behind infected clippings, or walking through diseased areas and then into healthy sections can all contribute to the movement of the fungus.
If a lawn is watered too frequently or at the wrong times, moisture lingers on the grass and creates an ideal environment for dollar spot spores to take hold. The fungus can also survive in the thatch layer of soil for extended periods, even when symptoms are not visible. If conditions become favorable again, the disease can quickly reappear, especially if preventive measures are not taken.
While dollar spot does not kill the roots of grass, it can cause significant damage to the turf, weakening it over time. A mild case of dollar spot may only cause temporary discoloration, with the grass recovering once conditions improve. However, severe or repeated infections can thin out the lawn, leaving it more vulnerable to other diseases, pests, and weed invasions.
Weakened grass is also less able to withstand environmental stressors like drought and extreme temperatures. If dollar spot is left untreated for an extended period, the affected patches may fail to recover, resulting in permanent thinning or bare spots that require overseeding or lawn renovation.
Without question, prevention is always easier than curative treatments when it comes to lawn disease. Many fungal lawn diseases seek out struggling lawns, and dollar spot is no different! Avoiding excess moisture is the best way to prevent dollar spot because this disease thrives in wet, humid conditions. Follow the tips below, and you should have a lawn that is free from dollar spot throughout the growing season.
While curative treatments are not nearly as effective as preventive maintenance, there are still some options available to you if your lawn is dealing with a severe infection. Propiconazole and azoxystrobin are common ingredients in fungicides used to treat dollar spot. These chemicals can be sprayed directly onto infected turf, but you must be careful not to apply too much, or everything green in your yard could suffer!
To be sure you are getting the best and most comprehensive disease control, call a professional lawn care company. The pros have years of experience dealing with fungicides, so you don't have to worry about damaging your lawn due to inexperience. Call Simple Lawns or your local lawn care company today, and take back your turf!