Dollar Spot, a common fungal lawn disease, is a frequent unwelcome guest on properties across Virginia and much of the United States. Imagine stepping onto your lawn and noticing a scattering of bleached patches, each about the size of a silver dollar. It's a disheartening sight for any lawn care enthusiast, and homeowners may start to panic when these spots and patches begin to spread. If ignored, this disease can wreak havoc on your lawn's health and appearance.
That is why the Blue Sky team is here to equip you with the knowledge needed to identify, prevent, and conquer Dollar Spot. Keep reading if you are ready to take back control of your lawn!
Dollar Spot earns its name from the distinctive round patches it creates on your lawn, often resembling the size of a silver dollar. These patches usually start as small, straw-colored spots and can gradually enlarge if the conditions are favorable for the fungus. If your lawn were experiencing an infection from other patch-type diseases, like Brown Patch or Large Patch, the infected spots on your lawn would have a much larger circumference. The smaller circular patches of Dollar Spot will often merge together to form patches of irregularly shaped, straw-colored spots that may appear to be slightly sunken into the soil.
Dollar Spot lawn disease is caused by fungi that belong to the Clarireedia genus. These fungi will not attack the roots or crowns of the grass blades they infect, but grass blades will show visible signs of damage. Individual grass blades that have been infected with Dollar Spot will develop lesions that are a pale yellow color, and these lesions often feature a brownish border around the discolored spot on the leaf. Look for the following in your lawn:
While Dollar Spot doesn't typically kill lawns outright, it can inflict significant damage. The disease primarily affects the blades of grass, causing them to weaken, discolor, and eventually die back. This can leave your lawn looking thin, patchy, and unsightly. However, in most cases, the crown and roots of the grass remain intact, allowing for recovery with proper care and treatment. If left unchecked and allowed to spread extensively, Dollar Spot can severely weaken the turf, making it more susceptible to other diseases and stresses.
As previously mentioned, infected blades of grass develop hourglass-shaped lesions. The lesions caused by Dollar Spot are known to expand and take over the plant when they are allowed to go untreated. Grass affected by Dollar Spot will not die immediately, but severe infections can and will lead to the death of those infected patches of grass. Therefore, early detection and prompt intervention are crucial in preventing long-term damage and ensuring your lawn's survival.
Human interference and physical transfer of fungal spores are the most common ways the Dollar Spot spreads from one area to another. Dollar Spot thrives in lawns that have short turfgrass, and items like lawn mowers, trimers, clippers, and other yard care tools are frequently responsible for the spread of Clarireedia fungi. Below are a few of the top sources of a Dollar Spot invasion.
Aside from physical transference, Dollar Spot fungi will replicate and spread on its own if there is a suitable host within reach. Mycelium from the invading fungi spreads across the tips of grass blades, especially when there is excess moisture present. This mycelium will appear as a light, cotton-like material that spans gaps between glades of grass, and it is often said to look similar to a cobweb. Any area of your lawn that is infected with Dollar Spot will likely spread if corrective measures are not taken.
Several factors conspire to create the perfect environment for Dollar Spot to flourish. Like many other fungal lawn diseases, moderate temperatures and high humidity can cause Dollar Spot to develop. The ideal conditions for Dollar Spot include daytime temperatures between 60°F and 80°F, humid or rainy weather, and cooler nighttime temperatures. Prolonged leaf wetness, whether from dew, rain, or irrigation, provides an ideal breeding ground for the fungus. Lawns deficient in nitrogen are more susceptible to infection, as the weakened grass blades become easy targets for the fungus.
Here in Virginia, lawns filled with the popular Zoysiagrass are particularly susceptible to a Dollar Spot invasion if conditions are ideal for its growth. In addition to grass type, the condition of your turf also factors into how quickly Dollar Spot can spread. Lawns that consistently stay damp throughout the heat of the day and into the cool night are especially susceptible to infection. Because of this, watering your lawn early in the morning, when it has enough time to dry in the sunlight, is always the best option. Below is a list of a few common causes of Dollar Spot:
