Americans have a love affair with lawns that is here to stay, according to the LSU Agricultural Center. Because of this, in warmer parts of the country, Bermuda grass is a popular grass for lawns. Bermuda grass is a native of Africa. It will grow in a wide range of soil types and is very heat and drought resistant. When Bermuda develops problems, it can be difficult to diagnose. Bermuda plants may be subject to over 100 different disease types, according to NC State University. Other problems that can affect Bermuda range from fungus, pests or cultural management problems.
Stand at one end of your lawn and look across the lawn for disease symptoms. Diseases that affect Bermuda grass leave distinct signs. Many problems with your lawn leave discolored marks known as spots, patches, circles, rings or irregular stands of grass. The size and shape of a discolored area determines whether the area is a spot, patch, ring, circle or irregular growth.
Spots are less than 4 inches in diameter. Circles are perfectly round and larger than 4 inches. Patches are irregular and larger than 4 inches. Rings are discolored areas with healthy lawn growth both inside and out of the discolored area. Fungus diseases that leave signs such as these include spring dead spot, dollar spot, brown patch and pythium.
Pick a sprig of unhealthy grass and look at the individual plant's symptoms under a magnifying glass. Do not pick completely dead sprigs or completely healthy ones. Symptoms to look for include leaf spots, lesions on the blades or stem, blight, in which the blades of grass are wilting, and dieback, in which individual blades are turning brown and rotting at the crown or roots. Bermuda grass is prone to fungus diseases that cause leaf spot.
Dig into the thatch layer and soil with a trowel to search for problems in the soil. Examples of signs at the soil level include the presence of bugs that eat the stem or root of a plant. Bugs that feed on Bermuda grass include white grubs, mealybugs, Bermuda grass mites, sod webworms and cut worms. Bermuda grass that is frequently watered in summer is prone to developing problems with fungus, which may appear in cottony masses, jelly-like structures, stringy spore or round, hard fruiting fungus in the thatch layer called sclerotia. Bermuda grass is also subject to attack by nematodes, which leave behind swollen roots.
Note the terrain of your soil and where the symptoms occur in relation to this terrain. Fungal problems are more likely to occur in low-lying, soggy areas of soil. Thin patches where moss or crabgrass may become established will occur in shady areas where Bermuda grass grows thin from lack of sunlight.
Listen to recent weather reports. Fungal diseases are more likely to establish themselves during wet periods.
Keep records of your fertilizer amounts and times. If brown spots appear on your lawn, note the amount of fertilizer you applied and when you applied it. Overabundance of nitrogen can cause your lawn to burn, which appears as patchy brown spots. Nitrogen burn can also weaken a lawn and leave it open to attack by fungal infections.