Fungal problems are the most common cause for lawn diseases. Although some fungal diseases don't destroy a lawn, they can easily ruin a lawn's appearance, causing a homeowner embarrassment, expense and frustration. Once a fungus starts taking a section of grass, it can easily spread to an entire lawn, stealing moisture and nutrients that are essential for grass to grow. Although a lawn fungus can be hard to diagnose, there are a few basic symptoms suggesting a problem. Common signs of a lawn fungus include spots on leaves and leaf discoloration.
Fungi are microscopic thread-like organisms that are spread by spores that are either waterborne or airborne. Functioning as seeds, these spores create infections if an environment has favorable conditions and a host is weak or vulnerable to being attacked. Disease results when the fungus (pathogen) is on a susceptible grass under the right environmental conditions.
Dollar spot is a lawn fungal disease that gets its name from the infected lawn spots that look like dollar coins. This fungus shows cob-webbing spots in morning hours that turn brown later in the day. It thrives on lawns that are dry and undernourished.
Fairy ring has symptoms of green circular areas that seem to be growing faster than other parts of a lawn. It's a fungus that is typically the result of excess rainfall and is found mostly in the Pacific Northwest.
Brown patch, also known as summer patch, kills a circle of grass that's as wide as 2 feet in diameter, according to Great Landscaping Ideas.com. It causes grass thinning and discoloration in infected areas.
Many people think their lawns are suffering from a fungal disease when their discolored, dried-out lawn patches are actually the result of dog urine burns. Sometimes when a dog urinates on a lawn it creates small spots of brown dead grass that resemble a lawn fungus. If brown areas become green when watered heavily, it's a dog-urine burn rather than a lawn fungus.
Usually the growth of a fungal disease is linked with caretakers not properly performing certain management practices such as giving grass enough water at the right times. Fungal diseases can be connected with planting the wrong type of grass or failing to provide sufficient sunlight to a lawn. Maintaining good soil aeration is important, in addition to timely fertilization using proper amounts and balanced nutrients. It also helps to keep records of herbicides, mowing height, fertilizer treatments, watering frequency and other activities.
Warning and Types of Fungicides
Because fungal lawn diseases can become resistant to fungicides after using them repeatedly, it's beneficial to use different types of fungicides.
There are three main types of fungicides: contact, systemic and penetrant fungicides. Contact fungicides need to be applied only once and remain on a plant, killing spores. Systemic fungicides are applied to leaves, but move throughout a plant. Penetrant fungicides are a preventative treatment for stopping pathogens from growing.