A beautiful lawn can be the hallmark of an attentive and conscientious homeowner. One of the most common problems on lawns is brown patch, a disease that can kill large areas of grass at once. Brown patch grows from fungus and it can affect any type of lawn grass.
Brown patch affects nearly all types of turf grass. As its name suggests, brown patch features a patch of brown in your lawn that starts off small, taking a circular or horseshoe shape. The infected area can easily span several feet of your lawn at one time; the disease can spread within 24 to 36 hours of the fungus taking hold in the grass. A yellowing, wilting ring often surrounds the brown patches as the brown patch spreads.
Warm temperatures--ranging between 75 and 85 degrees Fahrenheit and staying above 65 degrees Fahrenheit--will contribute to the rapid spread of the brown patch fungus. Moisture also contributes to fungal growth, so grasses with poor drainage and lack of airflow are more likely to develop brown patch. Excessive nitrogen in the soil--often a result of overfertilizing--can also help the disease grow and spread.
Eliminate shady areas in your lawn; direct sunlight in the grass will encourage water evaporation and can increase temperatures above 85 degrees Fahrenheit, which will help to kill the fungus. Remove overhanging branches or trees.
Aerate your lawn at least once per year. Most landscapers and gardeners choose to aerate in either early spring or early fall. Aeration involves pulling small cores of soil from the lawn to increase airflow and water drainage.
Control the nitrogen in your lawn. Follow a fertilization schedule that is appropriate for your grass type. If you are unsure about what type of fertilizer to use, how much to use or how often to fertilizer, consult with experts at garden centers, nurseries or extension services.
While properly caring for the grass can go a long way toward preventing the development of brown patch, there are other factors that gardeners may not consider than can affect a lawn. Prevent pets and other animals from urinating or defecating on your lawn, as this can increase the amount of nitrogen in the soil.
Reduce foot traffic across your lawn as much as possible. Walking on the lawn will compact the soil, creating more airflow and drainage problems.
Gardeners and landscapers use fungicides to treat excessive cases of brown patch. The most common fungicides include benomyl and chlorothalonil. You may find these chemicals available in garden centers and nurseries.