Answer: Before proceeding with any type of action, make sure the grass is not turning yellow/brown because it's going dormant. Dormancy is a natural reaction in turfgrasses, prompted by seasonal temperature changes. Cool-season grasses go dormant in the heat of summer, warm-season grasses in winter. Dormancy is a resting period, so it is important not to fertilize during dormancy.
If you have warm season grass and it's turning yellow during the warm season, it may just need to be fed or watered more frequently. Lawns that are not getting enough nitrogen (the key component of lawn fertilizer) will begin to change to light green and then yellow. The color change usually begins to show first in the lower leaves. Reduced growth is also a sign of nitrogen deficiency. Normally the entire lawn is affected. Adding nitrogen will help restore the green color if the fertilization is done properly. Applying too much at the wrong time can do more harm than good. Grass cycling adds nitrogen naturally to the lawn.
Another reason for discoloration could be lack of iron in your soil. Some of the more common areas of the yard that might find themselves turning yellow are those adjacent to things made of concrete. Driveways, sidewalks and concrete planters can be the culprits. The high alkaline content in concrete tends to absorb the iron found in soil, reducing the amount of iron your lawn or garden receives.
Iron deficiency appears in patches. Blades may yellow but the veins retain their green color. Growth may not be affected. Alkaline soils (such as in the midwestern and western states) are especially susceptible to iron deficiencies.
Iron is a natural soil supplement that neutralizes alkalinity and helps replenish the iron that occurs naturally in the soil. Apply as directed on the package. Remove the product from masonry or concrete surfaces before watering to avoid staining.
Yellowing grass is also a symptom of several lawn diseases. Should there be evidence of disease or insect pests, get a positive identification of the problem before trying to treat it. Your local Cooperative Extension Service can help.
Best wishes with your lawn!
Q&A Library Searching Tips