Anthracnose (Colletotrichum cereale) is a destructive and persistent lawn disease that can cause serious devastation to your lawn. As a fungal infection that affects various grass types, particularly in warmer climates, anthracnose can cause yellowing, thinning, and even rotting of grass that leads to unsightly patches spreading across your turf.
To help you identify and prevent this disease in your lawn before damage is done, we have put together this guide for all you need to know about anthracnose lawn disease and how to avoid it.
Anthracnose can be tricky to identify in its early stages because its symptoms can resemble other common lawn problems, such as drought stress, nutrient deficiencies, or even other fungal diseases. The first signs of anthracnose usually appear as irregular yellow or brown patches in the lawn, with individual grass blades showing dark brown or black lesions. These lesions often start as small, water-soaked spots before expanding and darkening as the disease progresses.
As the infection worsens, the affected grass blades wilt, dry out, and become brittle, often giving the lawn a scorched or sunburned appearance. The most severe cases may exhibit rotting at the base of the grass blades, which causes the affected turf to thin out and die off in patches. This can lead to bare spots and uneven growth, making the lawn look weak and poorly maintained.
Luckily, there is one good way to differentiate anthracnose from other lawn conditions. If you inspect the infected areas closely, you may notice tiny, black fungal structures (known as fruiting bodies) at the base of the grass blades or along the stems, which is a clear indicator of an anthracnose infection. In fact, the term, "anthracnose" derives from various terms meaning "coal," "dark lesion," and "disease," hinting at the identifying traits.
Key Identifiers:
Anthracnose typically develops in the leaves of trees and other plants and spreads to the grass in your lawn. It can affect virtually all grass types under the right conditions. The disease is perhaps best known for infecting grass on golf greens, so short-mowed grasses are known to be at high risk. The severity of the disease often depends on environmental factors, grass health, and overall lawn maintenance practices.
Most Affected Grass Types:
This disease is caused by the Colletotrichum cereale fungus, which thrives in moist environments and can persist in lawns for long periods. The infection often appears during hot, humid summers or after extended periods of stress, such as drought, compacted soil, or poor nutrient balance. Anthracnose is primarily triggered by stress conditions that weaken the lawn and make it more susceptible to fungal infection.
One of the most common causes is prolonged moisture, as the fungus thrives in warm, humid environments where the grass remains wet for extended periods. Frequent rainfall, excessive irrigation, and poor drainage all create ideal conditions for anthracnose to develop and spread. It is important to remember that this disease will usually begin somewhere other than your lawn, such as a vegetable garden or in your shrubbery. Look for discolored leaves and vegetation throughout your yard in order to prevent diseases from spreading to your lawn.
In addition to excessively moist or wet conditions, and certainly in conjunction with such conditions, the following factors can quickly lead to anthracnose developing:
Anthracnose spreads primarily through fungal spores, which are carried by wind, water, lawn equipment, and foot traffic. Rain, irrigation, or even morning dew can splash spores from infected grass onto healthy blades, allowing the disease to spread quickly under favorable conditions. The fungus can also survive in the soil and thatch layer for long periods, remaining dormant until environmental conditions trigger an outbreak.
Lawn mowers and garden tools can unknowingly transfer fungal spores from one area to another if they aren’t cleaned properly after use. Similarly, walking through an infected area and then stepping onto healthy grass can contribute to the spread of the disease. Because anthracnose can remain in the soil, repeated infections are possible if the lawn isn’t properly managed.
Anthracnose can be a devastating lawn disease if left untreated, but its impact depends on how quickly it is identified and addressed. In mild cases, the disease may only cause temporary discoloration and thinning, which can be reversed with proper lawn care and environmental adjustments. However, in more severe infections, the fungus can rot the base of the grass, leading to plant death and permanent damage to the lawn.
If basal rot (also known as crown rot) anthracnose develops, large patches of grass may die off, leaving behind bare spots that become susceptible to weed invasion. Because anthracnose often targets weakened, nutrient-deficient or stressed turf, it can lead to long-term lawn deterioration if the underlying issues aren’t corrected. A severely infected lawn may take months to recover, requiring overseeding, aeration, and soil amendments to restore healthy grass growth.
The best way to protect your lawn from anthracnose is through proper lawn care and maintenance practices that strengthen grass health and reduce stress. Maintaining a consistent fertilization schedule is crucial to ensure that nutrient levels are maintained through the year. Avoid overusing quick-release fertilizers, which can cause rapid but weak growth, making grass more vulnerable.
Other tasks to be mindful of include irrigation habits, to ensure overwatering does not take palace, and mowing habits/lawn mower maintenance to prevent the spread of fungal spores from uncleaned equipment. Keep the tips below in mind to prevent lawn diseases from developing in your turf.
For more help dealing with lawn diseases on your property, call Pro Outdoor today to ask about our lawn care services for the Albany, GA area!
