A lawn is the centerpiece for landscape on many properties. A brown spotted lawn can leave a bad impression with neighbors and could lower the value of the property. Brown spots on a lawn are difficult to stop once they get started. Each type of brown spot causing pathogen has certain strains of grass that it infests most frequently, but the diseases can affect many different types of grass in conditions that render the grasses vulnerable to disease.
Grass does not thrive on constant wetness. Though watering a brown lawn can seem a logical way to treat the problem, many brown spots are caused by overwatering.
Types of lawn diseases that can contribute to brown spots include brown patch, dollar spot, snow mold, blight and mildew. Kentucky bluegrass is most susceptible to dollar spot, leaf spot and mildew spot diseases, while the brown patch grass disease occurs most often in St. Augustine grass.
Attentive lawn care plays a key role in the prevention of brown spots on a lawn, including proper mowing and watering technique. The mower should be set to the correct height for the variety of grass, and the lawn should be allowed to dry between waterings.
Most lawn spot diseases can be identified by the properties of the spot. The brown patch disease has large brown spots that can be several feet wide. The dollar spot disease looks like several smaller spots, 1 to 5 inches across, clustered together. The leaf spot lawn disease looks like a brown spot with darker-colored edges near the outside of the spot.
Watering in the early morning to avoid a wet lawn in the evening can help prevent sitting water, which can encourage the wet conditions that render a lawn prone to brown spots.