Why Is My Lawn Turning Yellow?

A yellowing lawn not only reduces aesthetic appeal of the landscape but indicates a health problem requiring immediate action. Care for yellow grass with good cultural practices to control the problem and restore lush green color and vigor. Lawns also turn yellow during dormant phases, allowing them to rest naturally until they turn green again.

Pests severely damage grass blades and roots, causing the lawn to appeal dull, faded and yellow. Leaf hoppers and chinch bugs sap essential juices from grass blades, causing wilt and yellowing; grubs, scale and nematodes chew on grass roots. Although specific treatment varies according to the type of pest and scale of infestation, control is achieved through insecticide application followed by deep irrigation to help release chemicals into the soil. If the infestation is severe and the damage is beyond repair, pull grass plants out of the soil and re-seed bare patches.

Disease-infested lawns take on a yellow appearance and are usually corrected with proper care. Dollar spot, Rhizoctonia yellow patch, summer patch and fusarium patch are fungal diseases that give infected parts of the lawn a straw coloring. Because fungal spores of the diseases infest stressed grass, follow a regular fertilizing, watering and mowing schedule to reduce stress. Treat diseased parts with a registered fungicide applied at regular intervals so the grass regains its health and color.

Improper cultural practices increase stress on lawn grass, making it susceptible to pest damage or disease. Water, mow and fertilize your grass according to requirements for each type. Ideally, water your grass infrequently but deeply, providing 1 1/2 inches of water weekly, using a trickle irrigation system. Don't water the grass again until it shows signs of wilting, which include footprints or mower tracks up to a half hour after the traffic passed. Although grass height varies according to the type and season, keep your lawn grass 2 to 3 inches tall. Increase the height slightly during the summer to keep the roots cool, and avoid trimming more than a third of the blade length in one mowing session. Lack of nitrogen or improper fertilization produces a dull, yellow appearance. Give your lawn 1 to 1 1/2 lbs. of nitrogen-rich fertilizer per 1,000 square feet.

Grass that grows next to walkways, driveways, sidewalks and other things made from concrete usually appears yellow, indicating an iron deficiency. This is because the high-alkaline content in concrete absorbs the iron in the soil, depleting reserves for grass. Feed the grass iron supplements to retain its natural color. Physical damage to grass in the form of excessive foot traffic, dog urine, gasoline spills and overapplication of pesticides causes yellowing grass.